Downloaded 14 times
![Example - 2
str1 = 'hello javatpoint' #string str1
str2 = ' how are you' #string str2
print (str1[0:2]) #printing first two character using slice
operator
print (str1[4]) #printing 4th character of the string
print (str1*2) #printing the string twice
print (str1 + str2) #printing the concatenation of str1 a
nd str2
Output:
he o hello javatpointhello javatpoint hello javatpoint
how are you](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-64-2048.jpg)
![• List:
• Lists in Python are like arrays in C, but lists can
contain data of different types. The things put
away in the rundown are isolated with a comma
(,) and encased inside square sections [].
• To gain access to the list's data, we can use slice
[:] operators. Like how they worked with strings,
the list is handled by the concatenation operator
(+) and the repetition operator (*).](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-65-2048.jpg)
![Example:
list1 = [1, "hi", "Python", 2]
#Checking type of given list
print(type(list1))
#Printing the list1
print (list1)
# List slicing
print (list1[3:])
# List slicing
print (list1[0:2])
# List Concatenation using + operator
print (list1 + list1)
# List repetation using * operator
print (list1 * 3)
Output:
[1, 'hi', 'Python', 2] [2] [1, 'hi'] [1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2]
[1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-66-2048.jpg)
![Example:
tup = ("hi", "Python", 2)
# Checking type of tup
print (type(tup))
#Printing the tuple
print (tup)
# Tuple slicing
print (tup[1:])
print (tup[0:1])
# Tuple concatenation using + operator
print (tup + tup)
# Tuple repatation using * operator
print (tup * 3)
# Adding value to tup. It will throw an error.
t[2] = "hi"](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-68-2048.jpg)
![Output:
<class 'tuple'>
('hi', 'Python', 2)
('Python', 2)
('hi',)
('hi', 'Python', 2, 'hi', 'Python', 2)
('hi', 'Python', 2, 'hi', 'Python', 2, 'hi', 'Python', 2)
Traceback (most recent call last):
File "main.py", line 14, in <module>
t[2] = "hi";
TypeError: 'tuple' object does not support item
assignment](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-69-2048.jpg)
![Dictionary
• A dictionary is a key-value pair set arranged in any order. It
stores a specific value for each key, like an associative
array or a hash table. Value is any Python object, while the
key can hold any primitive data type.
• The comma (,) and the curly braces are used to separate
the items in the dictionary.
• Look at the following example.
d = {1:'Jimmy', 2:'Alex', 3:'john', 4:'mike'}
# Printing dictionary
print (d)
# Accesing value using keys
print("1st name is "+d[1])
print("2nd name is "+ d[4])
print (d.keys())
print (d.values())](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-70-2048.jpg)
![• Output:
1st name is Jimmy
2nd name is mike
{1: 'Jimmy', 2: 'Alex', 3: 'john', 4: 'mike'}
dict_keys([1, 2, 3, 4])
dict_values(['Jimmy', 'Alex', 'john', 'mike'])](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-71-2048.jpg)
![Code:
# Python program to demonstrate the application of iskeyword()
# importing keyword library which has lists
import keyword
# displaying the complete list using "kwlist()."
print("The set of keywords in this version is: ")
print( keyword.kwlist )
Output:
The set of keywords in this version is : ['False', 'None', 'True',
'and', 'as', 'assert', 'async', 'await', 'break', 'class', 'continue',
'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global',
'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass',
'raise', 'return', 'try', 'while', 'with', 'yield']
By calling help(), you can retrieve a list of currently offered
keywords:
Code
help("keywords")](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-78-2048.jpg)
![V. Literal Collections.
• Python provides the four types of literal
collection such as List literals, Tuple literals, Dict
literals, and Set literals.
List:
• List contains items of different data types. Lists
are mutable i.e., modifiable.
• The values stored in List are separated by
comma(,) and enclosed within square
brackets([]). We can store different types of data
in a List.](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-85-2048.jpg)
![Example - List literals
list=['John',678,20.4,'Peter']
list1=[456,'Andrew']
print(list)
print(list + list1)
Output:
['John', 678, 20.4, 'Peter']
['John', 678, 20.4, 'Peter', 456, 'Andrew']
• Dictionary:
• Python dictionary stores the data in the key-value
pair.
• It is enclosed by curly-braces {} and each pair is
separated by the commas(,).](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-86-2048.jpg)
![Example
dict = {'name': 'Pater', 'Age':18,'Roll_nu':101}
print(dict)
Output:
{'name': 'Pater', 'Age': 18, 'Roll_nu': 101}
Tuple:
Python tuple is a collection of different data-type. It is
immutable which means it cannot be modified after
creation.
It is enclosed by the parentheses () and each element is
separated by the comma(,).
Example
tup = (10,20,"Dev",[2,3,4])
print(tup)
Output:
(10, 20, 'Dev', [2, 3, 4])](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-87-2048.jpg)
![Program Code:
Now we give code examples of Membership
operators in Python. The code is given below -
x = ["Rose", "Lotus"]
print(' Is value Present?', "Rose" in x)
print(' Is value not Present?', "Riya" not in x)
Output:
Now we compile the above code in Python, and
after successful compilation, we run it. Then the
output is given below -
Is value Present? True
Is value not Present? True](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-109-2048.jpg)
![Identity Operators
Program Code:
Now we give code examples of Identity operators
in Python. The code is given below -
a = ["Rose", "Lotus"]
b = ["Rose", "Lotus"]
c = a
print(a is c)
print(a is not c)
print(a is b)
print(a is not b)
print(a == b)
print(a != b)](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-110-2048.jpg)
![Code:
# Python program to show how the for loop works
# Creating a sequence which is a tuple of numbers
numbers = [4, 2, 6, 7, 3, 5, 8, 10, 6, 1, 9, 2]
# variable to store the square of the number
square = 0
# Creating an empty list
squares = []
# Creating a for loop
for value in numbers:
square = value ** 2
squares.append(square)
print("The list of squares is", squares)
Output:
The list of squares is [16, 4, 36, 49, 9, 25, 64, 100, 36, 1, 81, 4]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-143-2048.jpg)
![Code:
# Python program to show the working of range() functio
n
print(range(15))
print(list(range(15)))
print(list(range(4, 9)))
print(list(range(5, 25, 4)))
Output:
range(0, 15)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
[4, 5, 6, 7, 8]
[5, 9, 13, 17, 21]
• To iterate through a sequence of items, we can apply
the range() method in for loops. We can use indexing
to iterate through the given sequence by combining it
with an iterable's len() function. Here's an illustration.](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-151-2048.jpg)
![Code:
# Python program to iterate over a sequence with the hel
p of indexing
tuple_ = ("Python", "Loops", "Sequence", "Condition", "R
ange")
# iterating over tuple_ using range() function
for iterator in range(len(tuple_)):
print(tuple_[iterator].upper())
Output:
PYTHON
LOOPS
SEQUENCE
CONDITION
RANGE](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-152-2048.jpg)
![Pass by Reference vs. Pass by Value:
In the Python programming language, all parameters are passed by
reference. It shows that if we modify the worth of contention within a
capability, the calling capability will similarly mirror the change. For
instance,
Code
# Example Python Code for Pass by Reference vs. Value
# defining the function
def square( item_list ):
'''''''This function will find the square of items in the list'''
squares = [ ]
for l in item_list:
squares.append( l**2 )
return squares
# calling the defined function
my_list = [17, 52, 8];
my_result = square( my_list )
print( "Squares of the list are: ", my_result )
Output:
Squares of the list are: [289, 2704, 64]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-167-2048.jpg)
![Code:
# Python code to demonstrate the use of variable-length arguments
# Defining a function
def function( *args_list ):
ans = []
for l in args_list:
ans.append( l.upper() )
return ans
# Passing args arguments
object = function('Python', 'Functions', 'tutorial')
print( object )
# defining a function
def function( **kargs_list ):
ans = []
for key, value in kargs_list.items():
ans.append([key, value])
return ans
# Paasing kwargs arguments
object = function(First = "Python", Second = "Functions", Third = "Tutorial")
print(object)](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-178-2048.jpg)
![Output:
['PYTHON', 'FUNCTIONS', 'TUTORIAL']
[['First', 'Python'], ['Second', 'Functions'], ['Third',
'Tutorial']]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-179-2048.jpg)
![range()
we use range ( ) function in order to print values in sequence
example:
>>> for i in range(1,6):
print(i)
Output
1
2
3
4
5
sorted()
Like we’ve seen before, sorted() prints out a sorted version of an iterable. It does not,
however, alter the iterable.
>>> sorted('Python')
Output
[‘P’, ‘h’, ‘n’, ‘o’, ‘t’, ‘y’]
sum()
The function sum() takes an iterable as an argument, and returns the sum of all values.
>>> sum([3,4,5],3)
Output
15](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-196-2048.jpg)
![other built in functions :
int(), float(), str(), complex( ), list ( ) , tuple ( ) , set ( ) .
• print(int(10.5)) #converting float value to int
print(int("10")) #converting string to int
• print(float(10)) #converting int to float
print(float("10.5")) #converting string to float
print(str(10)) #converting int to str
• print(str(10.5)) #converting float to str
• print(complex(1,2.3))#converting int and float numbers
to complex print(list((1,2.4,"btech")))
#converting tuple to list print(tuple([1,2.4,"btech"]))
#converting list to tuple print(set([1,2.4,"btech"]))
#converting list to set](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-198-2048.jpg)
![output:
10
10
10.0
10.5
10
10.5 (1+2.3j)
[1, 2.4, 'btech']
(1, 2.4, 'btech')
{'btech', 1, 2.4}](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-199-2048.jpg)
![Example:
• print(int(10.5)) #converting float value to int
print(int("10")) #converting string to int
• print(float(10)) #converting int to float
print(float("10.5")) #converting string to float
print(str(10)) #converting int to str
• print(str(10.5)) #converting float to str
• print(complex(1,2.3))#converting int and float
numbers to complex print(list((1,2.4,"btech")))
#converting tuple to list
print(tuple([1,2.4,"btech"])) #converting list to
tuple print(set([1,2.4,"btech"]))
#converting list to set](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-209-2048.jpg)
![output:
10
10
10.0
10.5
10
10.5 (1+2.3j)
[1, 2.4, 'btech']
(1, 2.4, 'btech')
{'btech', 1, 2.4}](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-210-2048.jpg)
![Python - Internal types
Traceback:
when you get an error it is recommended that you should trace it
backward(traceback). Whenever the code gets an exception(error), the
traceback will give the information about what went wrong in the
code.The Python traceback contains great information that can help you
find what is going wrong in the code.
Example:
a = [1, 2, 3]
print(a[10])
output:.
Traceback (most recent call last):
File "", line 2, in print(a[10])
IndexError: list index out of range
In above example, we are trying to access the 10th element of the list. With
only 3 elements present in the list it will give Runtime error. When this
program is executed you will get the above traceback.](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-212-2048.jpg)
![Slice:
• A slice object is used to specify how to slice a
sequence. You can specify where to start the
slicing, and where to end. You can also specify
the step
• The slice() function returns a slice object.
Syntax
slice(start, end, step)
Example:
a = ("a", "b", "c", "d", "e", "f", "g", "h")
x = slice(3, 5)
print(a[x])
output:
('d', 'e')](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-213-2048.jpg)
![StringIndexingin Python
• Likeother programming languages,the indexing of the pythonstrings
starts from 0. Forexample,the string "HELLO"is indexed asgiven in
the below figure.
str="HELLO"
s t r [ 0]=H
s t r [ 1]=E
s t r [ 4]=O
• Python allows negative indexing for itssequences.
• The index of -1 refers to the last item, -2 to the second last item and
soon.
str[-1]=O
str[-2]=L
str[-4]=E](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-225-2048.jpg)
![StringOperatorsin Python
+ It is known asconcatenation operator used to join the strings.
* It is known asrepetition operator. It concatenates the multiple copies
of the samestring.
[ ] It is known asslice operator. It is used to accessthe sub-strings of a
particular string.
[ :] It is known asrange slice operator. Itis usedto accessthe characters
from the specifiedrange.
in It is known asmembership operator. It returns if aparticular sub-
string is present in the specifiedstring.
not in Itis also amembership operator and does the exact reverse of in. It
returns true if aparticular substring is not present in the specified
string.
r/R It is used to specify the raw string. Todefine any string asarawstring,
the character r or Ris followed by the string. Suchas"hello n
python".
% It is used to perform string formatting. It makesuseof the format
specifies usedin Cprogramming like %dor %fto map their valuesin
python.](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-227-2048.jpg)
![StringOperatorsin Python cont…
Example: “stropdemo.py”
str1 = "Hello"
str2 = " World"
print(str1*3) # prints HelloHelloHello
print(str1+str2) # prints Hello world
p r i n t ( s t r 1 [ 4 ] ) # prints o
pr int ( s t r 1[ 2 : 4 ] ) # prints l l
p r i n t ( ' w' i n str1) # prints false as w i s not present in str1
print('Wo' not i n str2) # prints false as W
o i s present i n s t r 2 .
pr int ( r 'Hello n world') # prints Hellon world as i t i s written
print("The string str1 : %s"%(str1)) # prints The string s t r : Hello
Output: pythonifdemo.py
HelloHelloHello
Hello World
o
ll
False
False
Hellon world
Thestring str1 : Hello](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-228-2048.jpg)
![StringFunctions& Methods in Python Cont..
☞ replace()
• In python, replace() method replaces theold sequence of
characters with the newsequence.
Syntax: str.replace(old, new[, count])
Example: strreplacedemo.py
s t r ="Java i s Obje c t- Orie n ted Java"
str2= str.replace("Java","Python")
print("Old String: n " , s t r )
print("New String: n " , s t r 2 )
str3 = str.replace("Java","Python",1)
p r i n t ( " n Old String: n " , s t r )
print("New String: n " , s t r 3 )
Output: pythonstrreplacedemo.py
Old String: Javais Object-Oriented and Java
New String: Python is Object-Oriented andPython
Old String: Javais Object-Oriented and Java
New String: Python is Object-Oriented andJava](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-232-2048.jpg)
![StringFunctions& Methods in Python Cont..
☞ split():
• In python, split() method splits the string into acomma separated list.
The string splits according to the spaceif the delimiter is not provided.
Syntax: s tr.s plit ( [s ep= "delimiter " ])
Example: strsplitdemo.py
str1 = "Python i s a programming language"
str2 = s t r 1 . s p l i t ( )
p r i n t ( s t r 1 ) ; p r i n t ( s t r 2 )
str1 = "Python,is,a,programming,language"
str2 = s t r 1 . s p l i t ( s e p = ' , ' )
p r i n t ( s t r 1 ) ; p r i n t ( s t r 2 )
Output: python strsplitdemo.py
Java i s a programming language
[ ' J a v a ' , ' i s ' , ' a ' , 'programming', 'language']
Java, i s , a, programming, language
[ ' J a v a ' , ' i s ' , ' a ' , 'programming', 'language']](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-233-2048.jpg)
![StringFunctions& Methods in Python Cont..
☞ find():
• In python, find() method finds substring in the given string and returns
index of the first match. It returns -1 if substring does not match.
Syntax: s t r. f i n d ( s u b [ , s t a r t [ , e n d ] ] )
Example: strfinddemo.py
str1 = "python i s a programming language"
str2 = s t r 1 . f i n d ( " i s " )
str3 = s tr1. find ( "java" )
str4 = s t r 1 . f i n d ( " p " , 5 )
str5 = s t r 1 . f i n d ( " i " , 5 , 2 5 )
p r i n t ( s t r 2 ,s t r 3,str4 , s tr5)
Output:
pythonstrfinddemo.py
7 -1 12 7](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-234-2048.jpg)
![StringFunctions& Methods in Python Cont..
☞ index():
• In python, index() method is sameasthe find() method except it returns
error on failure. Thismethod returns index of first occurred substring
and an error if there is no matchfound.
Syntax:
Example:
s t r . index(sub[, s t a r t [ , e n d ] ] )
strindexdemo.py
s tr1 = "python is a programming language"
str2 = s tr 1. index ("is" )
p r i n t ( s t r 2 )
str3 = str1.index("p",5)
p r i n t ( s t r 3 )
str4 = str1.index("i",5,25)
p r i n t ( s t r 4 )
s tr5 = s tr1. index( "java")
p r i n t ( s t r 5 )
Output:
pythonstrindexdemo.py
7
12
7
Substring not found](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-235-2048.jpg)
![Listin Python
• In python, alist canbe defined asacollection of values or
items.
• Theitems in the list are separated with the comma (,) and
enclosed with the square brackets [].
Syntax:
list-var =[ value1, value2, value3,….]
Example: “listdemo.py”
L1 = [ ]
L2 = [123,"python", 3.7]
L3 = [ 1 , 2, 3, 4, 5, 6]
L4 = ["C","Java","Python"]
p r i n t (L1)
p r i n t (L2)
p r i n t (L3)
p r i n t (L4)
Output:
pythonlistdemo.py
[ ]
[123, 'python', 3.7]
[ 1 , 2, 3, 4, 5, 6]
[ ' C ' , ' J a v a ' , ' P y t h o n ' ]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-243-2048.jpg)
![ListIndexingin Python
• Like string sequence, the indexing of the python lists starts from
0, i.e. the first element of the list is stored at the 0th index, the
second element of the list is stored at the 1st index, and soon.
• Theelements of the list canbe accessedby using theslice
operator [].
Example:
mylist=[‘banana’,’apple’,’mango’,’tomato’,’berry’]
• mylist[0]=”banana”
• mylist[2]=”mango”
mylist[1:3]=[”apple”,”mango”]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-245-2048.jpg)
![ListIndexingin Python cont…
• Unlike other languages, python provides us the flexibility to use
the negative indexing also. The negative indices are counted
from the right.
• The last element (right most) of the list has the index -1, its
adjacent left element is present at the index -2 and so on until
the left most elementis encountered.
Example: mylist=[‘banana’,’apple’,’mango’,’tomato’,’berry’]
• mylist[-1]=”berry”
• mylist[-3]=”mango”
mylist[-4:-2]=[“apple”,mango”]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-246-2048.jpg)
![ListOperatorsin Python
+
It is known asconcatenation operator used to concatenatetwo
lists.
*
It is known asrepetition operator. It concatenates themultiple
copies of the samelist.
[]
It is known asslice operator. It is usedto accessthe listitem
from list.
[:]
It is known asrange slice operator. It is used to accesstherange
of list items fromlist.
in
It is known asmembership operator. It returns ifaparticular
item is present in the specifiedlist.
not in
It is also amembership operator and It returns true if a
particular list item is not present in the list.](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-248-2048.jpg)
![ListOperatorsin Python cont…
Example: “listopdemo.py”
num=[1,2,3,4,5]
l a n g = [ ' p y t h o n ' , ' c ' , ' j a v a ' , ' p h p ' ]
print(num + lang) #concatenates two l i s t s
p r i n t (num * 2) #concatenates same l i s t 2 times
print (lang[ 2]) # prints 2nd index value
p r i n t ( lang[ 1: 4] ) #prints values from 1st to 3rd index.
p r i n t ( ' c p p ' i n lang) # prints False
print(6 not i n num) # prints True
Output: python listopdemo.py
[ 1 , 2, 3, 4, 5, 'python' , ' c ' , ' j a v a ' , ' p h p ' ]
[ 1 , 2, 3, 4, 5, 1, 2, 3, 4, 5]
java
[ ' c ' , ' j a v a ' , ' php' ]
False
True](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-249-2048.jpg)
![Howto updateor changeelements to a list?
• Python allows usto modify the list items by using the slice and
assignment operator.
• Wecan useassignment operator ( =) to change an item or a
range of items.
Example: “listopdemo1.py”
num=[1,2,3,4,5]
print(num)
num[2]=30
print(num)
num[1: 3] = [ 25, 36]
print(num)
num[4]="Python"
print(num)
Output:
python listopdemo1.py
[ 1 , 2, 3, 4, 5]
[ 1 , 2, 30, 4, 5]
[ 1 , 25, 36, 4, 5]
[ 1 , 25, 36, 4, 'Python']](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-250-2048.jpg)
![Howto delete or removeelements from a list?
• Python allows usto delete one or more items in alist by using
the delkeyword.
Example: “listopdemo2.py”
num = [1,2,3,4,5]
print(num)
del num[1]
print(num)
del num[1: 3]
print(num)
Output:
python listopdemo2.py
[ 1 , 2, 3, 4, 5]
[ 1 , 3, 4, 5]
[ 1 , 5]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-251-2048.jpg)
![Iterating aList
• A list can be iterated by using a for - in loop. A simple list
containing four strings can be iterated asfollows..
Example: “listopdemo3.py”
lang=[ 'python' ,'c','java' , 'php ‘]
print("The l i s t items are n " )
f o r i i n lang:
p r i n t ( i )
Output:
python listopdemo3.py
The l i s t items are
python
c
java
php](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-252-2048.jpg)
![ListFunctions& Methods in Python
• Python provides various in-built functions and methods which
canbe used with list. Thoseare
• len()
• max()
• min()
• sum()
• list()
☞ len():
• In Python, len() function is used to find the length of list,i.e it
returns the number of items in the list..
Syntax: l e n ( l i s t )
Example: listlendemo.py
num=[1,2,3,4,5,6]
print("length of l i s t :",len(num))
Output:
pythonlistlendemo.py
length of list :6
• sorted()
• append()
• remove()
• sort()
• reverse()
• count()
• index()
• insert()
• pop()
• clear()](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-254-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ max():
• In Python, max() function is used to find maximum value in the list.
Syntax: max(list)
Example: listmaxdemo.py
list1=[ 1,2,3,4,5,6]
l i s t 2 = [ ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ]
print("Max of l i s t 1 : ", m ax( list 1) )
print("Max of l i s t 2 : ", m ax( list 2) )
Output:
python listmaxdemo.py
Max of list1 :6
Max of list2 :python](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-255-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ min():
• In Python, min() function is used to find minimum value in the list.
Syntax: m i n ( l i s t )
Example: listmindemo.py
list 1=[ 1,2,3,4,5,6]
l i s t 2 = [ ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ]
print("Min of l i s t 1 :",min(list1))
print("Min of l i s t 2 :",min(list2))
Output:
pythonlistmindemo.py
Min of list1 :1
Min of list2 :c](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-256-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ sum():
• In python, sum() function returns sum of all values in the list. List
values must in numbertype.
Syntax: sum(list)
Example: listsumdemo.py
list 1=[ 1,2,3,4,5,6]
print("Sum of l i s t items : ", sum ( list 1) )
Output:
python listsumdemo.py
Sumof list items :21](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-257-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ list():
• In python, list() is used toconvert
into list.
given sequence (string or tuple)
Syntax: list(sequence)
Example: listdemo.py
str="python"
l i s t 1 = l i s t ( s t r )
p r i n t ( l i s t 1 )
Output:
python listdemo.py
['p', 'y', 't', 'h', 'o','n']](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-258-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ sorted():
• In python, sorted() function is used to sort all items of list in an
ascending order.
Syntax: s o r t e d ( l i s t )
Example: sorteddemo.py
num=[1,3,2,4,6,5]
l a n g = [ ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ]
print(sorted(num))
p r i n t ( sorted( la ng) )
Output:
python sorteddemo.py
[1, 2, 3, 4, 5,6]
['c', 'cpp', 'java','python']](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-259-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ append():
• In python, append() method adds an item to the end of the list.
Syntax: list.append(item)
where item may be number, string, list andetc.
Example: appenddemo.py
num=[1,2,3,4,5]
lang=[ 'python' ,'java']
num.append(6)
print(num)
lang.append( " cpp" )
print(lang)
Output:
python appenddemo.py
[1, 2, 3, 4, 5,6]
['python', 'java','cpp']](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-260-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ remove():
• In python, remove() method removes item from the list. It removes
first occurrence of item if list contains duplicate items. It throws an
error if the item is not present in the list.
Syntax: list.remove(item)
Example: removedemo.py
list 1=[ 1,2,3,4,5]
l i s t 2 = [ ' A ' , ' B ' , ' C ' , ' B ' , ' D ' ]
list1.remove(2)
p r i n t ( l i s t 1 )
l i s t 2 . remove( "B" )
p r i n t ( l i s t 2 )
list2.remove("E")
p r i n t ( l i s t 2 )
Output:
python removedemo.py
[1, 3, 4,5]
['A', 'C', 'B','D']
ValueError: xnot in list](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-261-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ sort():
• In python, sort() method sorts the list elements into descending or
ascending order. Bydefault, list sorts the elements into ascending
order. It takes an optional parameter 'reverse' which sorts the list
into descendingorder.
Syntax: list . sor t( [reverse=tr ue])
Example: sortdemo.py
list1=[6,8,2,4,10]
l i s t 1 . s o r t ( )
p r i n t ( " n After Sorting: n")
p r i n t ( l i s t 1 )
p r i n t ( "Descend ing Order: n")
list1.sort(reverse=True)
p r i n t ( l i s t 1 )
Output:
pythonsortdemo.py
After Sorting:
[2, 4, 6, 8 ,10]
Descending Order:
[10, 8, 6, 4 ,2]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-262-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ reverse():
• In python, reverse() method reverses elements of the list. i.e. the
last index value of the list will be present at 0th index.
Syntax: l i s t . r e v e r s e ( )
Example: reversedemo.py
list1=[6,8,2,4,10]
list1. reverse()
p r i n t ( " n After reverse: n")
p r i n t ( l i s t 1 )
Output:
python reversedemo.py
After reverse:
[10, 4, 2, 8 ,6]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-263-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ count():
• In python, count() method returns the number of times an element
appears in the list. If the element is not present in the list, it
returns 0.
Syntax: list.count( item)
Example: countdemo.py
num=[1,2,3,4,3,2,2,1,4,5,8]
cnt=num.count(2)
print("Count of 2 i s : " , c n t )
cnt=num.count(10)
p r i n t ( "Count of 10 i s : " , cnt) Output:
pythoncountdemo.py
Count of 2 is:3
Count of 10 is:0](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-264-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ index():
• In python, index () method returns index of the passedelement.If
the element is not present, itraises aValueError.
• If list contains duplicate elements, it returns index of first
occurred element.
• Thismethod takes two more optional parameters start and end
which are used to search index withinalimit.
Syntax: l i s t . index(item [ , s t a r t [ , end]])
Example: indexdemo.py
l i s t 1 = [ ' p ' , ' y ' , ' t ' , ' o ' , ' n ' , ' p ' ]
p r i n t ( l i s t 1 . i n d e x ( ' t ' ) )
P r i n t ( l i s t 1 . i n d e x ( ' p ' ) )
P r i n t ( l i s t 1 . i n d e x ( ' p ' , 3 , 1 0 ) )
P r i n t ( l i s t 1 . i n d e x ( ' z ' ) ) )
Output:
python indexdemo.py
2
0
5
Value Error](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-265-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ insert():
• In python, insert() method inserts the element at the specified
index in the list. The first argument is the index of the element
before which to insert theelement.
Syntax: list . ins er t ( i n de x, it em )
Example: insertdemo.py
num=[10, 20, 30, 40, 50]
num.insert( 4, 60)
print(num)
num.insert( 7, 70)
print(num)
Output:
pythoninsertdemo.py
[10, 20, 30, 40, 60,50]
[10, 20, 30, 40, 60, 50,70]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-266-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ pop():
• In python, pop() element removes an element present at specified
index from thelist.
Syntax: list.pop(index)
Example: popdemo.py
num=[10,20,30,40,50]
num.pop()
p r i n t (num)
num.pop( 2)
p r i n t (num)
num.pop( 7)
p r i n t (num)
Output:
pythonpopdemo.py
[10, 20, 30,40]
[10, 20, 40]
IndexError: Out of range](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-267-2048.jpg)
![ListFunctions& Methods in Python Cont..
☞ clear():
• In python, clear() method removes all the elements from the list.
It clears the list completely and returns nothing.
Syntax: l i s t . c l e a r ( )
Example: cleardemo.py
num=[10,20,30,40,50]
num.clear( )
print(num)
Output:
python cleardemo.py
[ ]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-268-2048.jpg)
![TupleIndexingin Python
• Like list sequence, the indexing of the python tuple starts from
0, i.e. the first element of the tuple is stored at the 0th index,
the second element of the tuple is stored at the 1st index, and
soon.
• Theelements of the tuple canbe accessedby using theslice
operator [].
Example:
mytuple=(‘banana’,’apple’,’mango’,’tomato’,’berry’)
• mytuple[0]=”banana”
• mytuple[2]=”mango”
mytuple[1:3]=[”apple”,”mango”]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-273-2048.jpg)
![TupleIndexingin Python cont…
• Unlike other languages, python provides us the flexibility to use
the negative indexing also. The negative indices are counted
from the right.
• The last element (right most) of the tuple has the index -1, its
adjacent left element is present at the index -2 and so on until
the left most elementis encountered.
Example: mytuple=*‘banana’,’apple’,’mango’,’tomato’,’berry’+
• mytuple[-1]=”berry”
• mytuple[-3]=”mango”
mytuple[-4:-2]=[“apple”,mango”]](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-274-2048.jpg)
![TupleOperatorsin Python
+
It is known asconcatenation operator used to concatenatetwo
tuples.
*
It is known asrepetition operator. It concatenates themultiple
copies of the sametuple.
[]
It is known asslice operator. It is usedto accessthe itemfrom
tuple.
[:]
It is known asrange slice operator. It is used to accesstherange
of items from tuple.
in
It is known asmembership operator. It returns ifaparticular
item is present in the specifiedtuple.
not in
It is also amembership operator and It returns true if a
particular item is not present in the tuple.](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-276-2048.jpg)
![TupleOperatorsin Python cont…
Example: “tupleopdemo.py”
num=(1,2,3,4,5)
l a n g = ( ' p y t h o n ' , ' c ' , ' j a v a ' , ' p h p ' )
print(num + lang) #concatenates two tuples
p r i n t (num * 2) #concatenates same tuple 2 times
print (lang[ 2]) # prints 2nd index value
p r i n t ( lang[ 1: 4] ) #prints values from 1st to 3rd index.
p r i n t ( ' c p p ' i n lang) # prints False
print(6 not i n num) # prints True
Output: python tupleopdemo.py
( 1 , 2, 3, 4, 5, 'python' , ' c ' , ' j a v a ' , ' p h p ' )
( 1 , 2, 3, 4, 5, 1, 2, 3, 4, 5)
java
( ' c ' , ' j a v a ' , ' php' )
False
True](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-277-2048.jpg)
![Howto addor removeelements from a tuple?
• Unlike lists, the tuple items cannot be updated or deleted as
tuples areimmutable.
• Todelete an entire tuple, we can usethe del keyword with the
tuple name.
Example: “tupledemo1.py”
t u p = ( ' p y t h o n ' , ' c ' , ' j a v a ' , ' p h p ' )
tup[3]="html"
p r i n t ( tup)
del tup[3]
p r i n t ( tup)
del tup
Output:
python tupledemo1.py
'tuple' object does not
support item assignment
'tuple' object doesn't
support item deletion](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-278-2048.jpg)
![TupleFunctions& Methods in Python Cont..
☞ tuple():
• In python, tuple() is used toconvert
into tuple.
given sequence (string or list)
Syntax: tuple(sequence)
Example: tupledemo.py
str="python"
t1=tuple(str)
p r i n t ( t 1 )
num=[1,2,3,4,5,6]
t2=tuple(num)
p r i n t ( t 2 )
Output:
pythontupledemo.py
('p', 'y', 't', 'h', 'o','n‘)
(1, 2, 3, 4, 5,6)](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-285-2048.jpg)
![TupleFunctions& Methods in Python Cont..
☞ index():
• In python, index () method returns index of the passedelement.If
the element is not present, itraises aValueError.
• If tuple contains duplicate elements, it returns index of first
occurred element.
• Thismethod takes two more optional parameters start and end
which are used to search index withinalimit.
Syntax: tuple.index(item [ , s t a r t [ , end]])
Example: indexdemo.py
t 1 = ( ' p ' , ' y ' , ' t ' , ' o ' , ' n ' , ' p ' )
p r i n t ( t 1 . i n d e x ( ' t ' ) )
P r i n t ( t 1 . i n d e x ( ' p ' ) )
Pr int ( t1.index( 'p' , 3,10))
P r i n t ( t 1 . i n d e x ( ' z ' ) ) )
Output:
python indexdemo.py
2
0
5
Value Error](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-288-2048.jpg)
![Method Description
clear() Removeall items form the dictionary.
copy() Returnashallowcopy of the dictionary.
fromkeys(seq[, v]) Return anewdictionary with keysfrom seq andvalueequalto v(defaults to None).
get(key[,d]) Return the value of key. If key doesnotexit, return d (defaults to None).
items() Return anewview of the dictionary'sitems (key, value).
keys() Returnanewview of the dictionary'skeys.
pop(key[,d])
Removethe item with key andreturn its value or d if key isnot found. If d is not provided
andkey isnot found, raisesKeyError.
popitem() Removeandreturn anarbitaryitem (key, value). Raises KeyError if the dictionary is empty.
setdefault(key[,d])
If key is in the dictionary,return its value. If not, insert key with avalueof d and
return d (defaults to None).
update([other]) Updatethe dictionary with the key/value pairs from other, overwritingexisting keys.
values() Returnanewview of the dictionary'svalues](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-302-2048.jpg)
![# Definition of country and capital
countries =['spain', 'france', 'germany', 'norway','india']
capitals =['madrid','paris', 'berlin', 'oslo','delhi']
I would like to print the capital of germany.
# Get index of 'germany': ind_ger
# Useind_ger to print out capital of Germany](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-305-2048.jpg)
![If you know how to accessadictionary, you can also
assignanew value to it. Toadd anew key-valuepair to
countryCapitals, you canusesomething like this:
countryCapitals[‘india’] =‘delhi’](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-307-2048.jpg)
![To remove a entry from dictionary, we can use del
method.
Remove norway
del (countryCapitals[‘norway’])](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-308-2048.jpg)
![Create aDictionary which records the major
cities ofeach state.
{state : [major cities] }](https://image.slidesharecdn.com/mergeresult20230914044135-230914050314-34add16d/75/PYTHON-UNIT-1-310-2048.jpg)
More Related Content
PYTHON UNIT 1
- 1.
- 2. What is Python •Python is a general-purpose, dynamic, high-level, and interpreted programming language. It supports Object Oriented programming approach to develop applications. It is simple and easy to learn and provides lots of high-level data structures. • Python is an easy-to-learn yet powerful and versatile scripting language, which makes it attractive for Application Development. • With its interpreted nature, Python's syntax and dynamic typing make it an ideal language for scripting and rapid application development. • Python supports multiple programming patterns, including object-oriented, imperative, and functional or procedural programming styles.
- 3. • Python isnot intended to work in a particular area, such as web programming. It is a multipurpose programming language because it can be used with web, enterprise, 3D CAD, etc. • We don't need to use data types to declare variable because it is dynamically typed, so we can write a=10 to assign an integer value in an integer variable. • Python makes development and debugging fast because no compilation step is included in Python development, and the edit-test-debug cycle is very fast. • Python has many web-based assets, open-source projects, and a vibrant community. Learning the language, working together on projects, and contributing to the Python ecosystem are all made very easy for developers.
- 4. • Because ofits straightforward language framework, Python is easier to understand and write code in. This makes it a fantastic programming language for novices. Additionally, it assists seasoned programmers in writing clearer, error-free code. • Python is an open-source, cost-free programming language. It is utilized in several sectors and disciplines as a result. • In Python, code readability and maintainability are important. As a result, even if the code was developed by someone else, it is easy to understand and adapt by some other developer. • Python has many third-party libraries that can be used to make its functionality easier. These libraries cover many domains, for example, web development, scientific computing, data analysis, and more.
- 5. Python Basic Syntax •There is no use of curly braces or semicolon in Python programming language. It is English-like language. But Python uses the indentation to define a block of code. Indentation is nothing but adding whitespace before the statement when it is needed. For example - def func(): statement 1 statement 2 ………………… ………………… statement N • In the above example, the statements that are the same level to the right belong to the function. Generally, we can use four whitespaces to define indentation. • Instead of Semicolon as used in other languages, Python ends its statements with a NewLine character. • Python is a case-sensitive language, which means that uppercase and lowercase letters are treated differently. For example, 'name' and 'Name' are two different variables in Python.
- 6. • In Python,comments can be added using the '#' symbol. Any text written after the '#' symbol is considered a comment and is ignored by the interpreter. This trick is useful for adding notes to the code or temporarily disabling a code block. It also helps in understanding the code better by some other developers. • 'If', 'otherwise', 'for', 'while', 'try', 'except', and 'finally' are a few reserved keywords in Python that cannot be used as variable names. These terms are used in the language for particular reasons and have fixed meanings. If you use these keywords, your code may include errors, or the interpreter may reject them as potential new Variables.
- 7. Why learn Python? •Python provides many useful features to the programmer. These features make it the most popular and widely used language. We have listed belo • Easy to use and Learn: Python has a simple and easy-to- understand syntax, unlike traditional languages like C, C++, Java, etc., making it easy for beginners to learn. • Expressive Language: It allows programmers to express complex concepts in just a few lines of code or reduces Developer's Time. • Interpreted Language: Python does not require compilation, allowing rapid development and testing. It uses Interpreter instead of Compiler. • Object-Oriented Language: It supports object-oriented programming, making writing reusable and modular code easy. • Open Source Language: Python is open source and free to use, distribute and modify. • Extensible: Python can be extended with modules written in C, C++, or other languages.
- 8. • Learn StandardLibrary: Python's standard library contains many modules and functions that can be used for various tasks, such as string manipulation, web programming, and more. • GUI Programming Support: Python provides several GUI frameworks, such as Tkinter and PyQt, allowing developers to create desktop applications easily. • Integrated: Python can easily integrate with other languages and technologies, such as C/C++, Java, and . NET. • Embeddable: Python code can be embedded into other applications as a scripting language. • Dynamic Memory Allocation: Python automatically manages memory allocation, making it easier for developers to write complex programs without worrying about memory management. • Wide Range of Libraries and Frameworks: Python has a vast collection of libraries and frameworks, such as NumPy, Pandas, Django, and Flask, that can be used to solve a wide range of problems. • Versatility: Python is a universal language in various domains such as web development, machine learning, data analysis, scientific computing, and more.
- 9. • Large Community:Python has a vast and active community of developers contributing to its development and offering support. This makes it easy for beginners to get help and learn from experienced developers. • Career Opportunities: Python is a highly popular language in the job market. Learning Python can open up several career opportunities in data science, artificial intelligence, web development, and more. • High Demand: With the growing demand for automation and digital transformation, the need for Python developers is rising. Many industries seek skilled Python developers to help build their digital infrastructure. • Increased Productivity: Python has a simple syntax and powerful libraries that can help developers write code faster and more efficiently. This can increase productivity and save time for developers and organizations. • Big Data and Machine Learning: Python has become the go-to language for big data and machine learning. Python has become popular among data scientists and machine learning engineers with libraries like NumPy, Pandas, Scikit-learn, TensorFlow, and more.
- 10. Where is Pythonused? • Python is a general-purpose, popular programming language, and it is used in almost every technical field. The various areas of Python use are given below. • Data Science: Data Science is a vast field, and Python is an important language for this field because of its simplicity, ease of use, and availability of powerful data analysis and visualization libraries like NumPy, Pandas, and Matplotlib. • Desktop Applications: PyQt and Tkinter are useful libraries that can be used in GUI - Graphical User Interface-based Desktop Applications. There are better languages for this field, but it can be used with other languages for making Applications. • Console-based Applications: Python is also commonly used to create command-line or console-based applications because of its ease of use and support for advanced features such as input/output redirection and piping. • Mobile Applications: While Python is not commonly used for creating mobile applications, it can still be combined with frameworks like Kivy or BeeWare to create cross-platform mobile applications.
- 11. • Software Development:Python is considered one of the best software-making languages. Python is easily compatible with both from Small Scale to Large Scale software. • Artificial Intelligence: AI is an emerging Technology, and Python is a perfect language for artificial intelligence and machine learning because of the availability of powerful libraries such as TensorFlow, Keras, and PyTorch. • Web Applications: Python is commonly used in web development on the backend with frameworks like Django and Flask and on the front end with tools like JavaScript and HTML. • Enterprise Applications: Python can be used to develop large- scale enterprise applications with features such as distributed computing, networking, and parallel processing. • 3D CAD Applications: Python can be used for 3D computer- aided design (CAD) applications through libraries such as Blender. • Machine Learning: Python is widely used for machine learning due to its simplicity, ease of use, and availability of powerful machine learning libraries.
- 12. • Computer Visionor Image Processing Applications: Python can be used for computer vision and image processing applications through powerful libraries such as OpenCV and Scikit-image. • Speech Recognition: Python can be used for speech recognition applications through libraries such as SpeechRecognition and PyAudio. • Scientific computing: Libraries like NumPy, SciPy, and Pandas provide advanced numerical computing capabilities for tasks like data analysis, machine learning, and more. • Education: Python's easy-to-learn syntax and availability of many resources make it an ideal language for teaching programming to beginners. • Testing: Python is used for writing automated tests, providing frameworks like unit tests and pytest that help write test cases and generate reports. • Gaming: Python has libraries like Pygame, which provide a platform for developing games using Python. • IoT: Python is used in IoT for developing scripts and applications for devices like Raspberry Pi, Arduino, and others.
- 13. • Networking: Pythonis used in networking for developing scripts and applications for network automation, monitoring, and management. • DevOps: Python is widely used in DevOps for automation and scripting of infrastructure management, configuration management, and deployment processes. • Finance: Python has libraries like Pandas, Scikit-learn, and Statsmodels for financial modeling and analysis. • Audio and Music: Python has libraries like Pyaudio, which is used for audio processing, synthesis, and analysis, and Music21, which is used for music analysis and generation. • Writing scripts: Python is used for writing utility scripts to automate tasks like file operations, web scraping, and data processing.
- 14. Python Popular Frameworksand Libraries • Python has wide range of libraries and frameworks widely used in various fields such as machine learning, artificial intelligence, web applications, etc. We define some popular frameworks and libraries of Python as follows. • Web development (Server-side) - Django Flask, Pyramid, CherryPy • GUIs based applications - Tk, PyGTK, PyQt, PyJs, etc. • Machine Learning - TensorFlow, PyTorch, Scikit-learn, Matplotlib, Scipy, etc. • Mathematics - Numpy, Pandas, etc. • BeautifulSoup: a library for web scraping and parsing HTML and XML • Requests: a library for making HTTP requests • SQLAlchemy: a library for working with SQL databases
- 15. • Kivy: aframework for building multi-touch applications • Pygame: a library for game development • Pytest: a testing framework for Python • Django REST framework: a toolkit for building RESTful APIs • FastAPI: a modern, fast web framework for building APIs • Streamlit: a library for building interactive web apps for machine learning and data science • NLTK: a library for natural language processing
- 16. Python Features • Pythonprovides many useful features which make it popular and valuable from the other programming languages. It supports object- oriented programming, procedural programming approaches and provides dynamic memory allocation. We have listed below a few essential features. 1) Easy to Learn and Use • Python is easy to learn as compared to other programming languages. Its syntax is straightforward and much the same as the English language. There is no use of the semicolon or curly-bracket, the indentation defines the code block. It is the recommended programming language for beginners. 2) Expressive Language • Python can perform complex tasks using a few lines of code. A simple example, the hello world program you simply type print("Hello World"). It will take only one line to execute, while Java or C takes multiple lines. 3) Interpreted Language • Python is an interpreted language; it means the Python program is executed one line at a time. The advantage of being interpreted language, it makes debugging easy and portable.
- 17. 4) Cross-platform Language Pythoncan run equally on different platforms such as Windows, Linux, UNIX, and Macintosh, etc. So, we can say that Python is a portable language. It enables programmers to develop the software for several competing platforms by writing a program only once. 5) Free and Open Source Python is freely available for everyone. It is freely available on its official website www.python.org. It has a large community across the world that is dedicatedly working towards make new python modules and functions. Anyone can contribute to the Python community. The open- source means, "Anyone can download its source code without paying any penny." 6) Object-Oriented Language Python supports object-oriented language and concepts of classes and objects come into existence. It supports inheritance, polymorphism, and encapsulation, etc. The object-oriented procedure helps to programmer to write reusable code and develop applications in less code. 7) Extensible It implies that other languages such as C/C++ can be used to compile the code and thus it can be used further in our Python code. It converts the program into byte code, and any platform can use that byte code.
- 18. 8) Large StandardLibrary It provides a vast range of libraries for the various fields such as machine learning, web developer, and also for the scripting. There are various machine learning libraries, such as Tensor flow, Pandas, Numpy, Keras, and Pytorch, etc. Django, flask, pyramids are the popular framework for Python web development. 9) GUI Programming Support Graphical User Interface is used for the developing Desktop application. PyQT5, Tkinter, Kivy are the libraries which are used for developing the web application. 10) Integrated It can be easily integrated with languages like C, C++, and JAVA, etc. Python runs code line by line like C,C++ Java. It makes easy to debug the code. 11. Embeddable The code of the other programming language can use in the Python source code. We can use Python source code in another programming language as well. It can embed other language into our code. 12. Dynamic Memory Allocation In Python, we don't need to specify the data-type of the variable. When we assign some value to the variable, it automatically allocates the memory to the variable at run time. Suppose we are assigned integer value 15 to x, then we don't need to write int x = 15. Just write x = 15.
- 19. Python History andVersions • Python laid its foundation in the late 1980s. • The implementation of Python was started in December 1989 by Guido Van Rossum at CWI in Netherland. • In February 1991, Guido Van Rossum published the code (labeled version 0.9.0) to alt.sources. • In 1994, Python 1.0 was released with new features like lambda, map, filter, and reduce. • Python 2.0 added new features such as list comprehensions, garbage collection systems. • On December 3, 2008, Python 3.0 (also called "Py3K") was released. It was designed to rectify the fundamental flaw of the language. • ABC programming language is said to be the predecessor of Python language, which was capable of Exception Handling and interfacing with the Amoeba Operating System. • The following programming languages influence Python: – ABC language. – Modula-3
- 20. Why the NamePython? • There is a fact behind choosing the name Python. Guido van Rossum was reading the script of a popular BBC comedy series "Monty Python's Flying Circus". It was late on-air 1970s. • Van Rossum wanted to select a name which unique, sort, and little-bit mysterious. So he decided to select naming Python after the "Monty Python's Flying Circus" for their newly created programming language. • The comedy series was creative and well random. It talks about everything. Thus it is slow and unpredictable, which made it very interesting. • Python is also versatile and widely used in every technical field, such as Machine Learning, Artificial Intelligence, Web Development, Mobile Application, Desktop Application, Scientific Calculation, etc.
- 21. Python Version List •Python programming language is being updated regularly with new features and supports. There are lots of update in Python versions, started from 1994 to current release. • A list of Python versions with its released date is given below.
- 24. Python Applications • Pythonis known for its general-purpose nature that makes it applicable in almost every domain of software development. Python makes its presence in every emerging field. It is the fastest-growing programming language and can develop any application. • Here, we are specifying application areas where Python can be applied.
- 25. 1) Web Applications Wecan use Python to develop web applications. It provides libraries to handle internet protocols such as HTML and XML, JSON, Email processing, request, beautifulSoup, Feedparser, etc. One of Python web-framework named Django is used on Instagram. Python provides many useful frameworks, and these are given below: • Django and Pyramid framework(Use for heavy applications) • Flask and Bottle (Micro-framework) • Plone and Django CMS (Advance Content management) 2) Desktop GUI Applications The GUI stands for the Graphical User Interface, which provides a smooth interaction to any application. Python provides a Tk GUI library to develop a user interface. Some popular GUI libraries are given below.
- 26. • Tkinter orTk • wxWidgetM • Kivy (used for writing multitouch applications ) • PyQt or Pyside 3) Console-based Application Console-based applications run from the command-line or shell. These applications are computer program which are used commands to execute. This kind of application was more popular in the old generation of computers. Python can develop this kind of application very effectively. It is famous for having REPL, which means the Read-Eval-Print Loop that makes it the most suitable language for the command-line applications. Python provides many free library or module which helps to build the command-line apps. The necessary IO libraries are used to read and write. It helps to parse argument and create console help text out-of-the-box. There are also advance libraries that can develop independent console apps.
- 27. 4) Software Development Pythonis useful for the software development process. It works as a support language and can be used to build control and management, testing, etc. SCons is used to build control. Buildbot and Apache Gumps are used for automated continuous compilation and testing. Round or Trac for bug tracking and project management. 5) Scientific and Numeric This is the era of Artificial intelligence where the machine can perform the task the same as the human. Python language is the most suitable language for Artificial intelligence or machine learning. It consists of many scientific and mathematical libraries, which makes easy to solve complex calculations. Implementing machine learning algorithms require complex mathematical calculation. Python has many libraries for scientific and numeric such as Numpy, Pandas, Scipy, Scikit-learn, etc. If you have some basic knowledge of Python, you need to import libraries on the top of the code. Few popular frameworks of machine libraries are given below. SciPy Scikit-learn NumPy Pandas Matplotlib
- 28. 6) Business Applications BusinessApplications differ from standard applications. E-commerce and ERP are an example of a business application. This kind of application requires extensively, scalability and readability, and Python provides all these features. 7) Audio or Video-based Applications Python is flexible to perform multiple tasks and can be used to create multimedia applications. Some multimedia applications which are made by using Python are TimPlayer, cplay, etc. The few multimedia libraries are given below. Gstreamer Pyglet QT Phonon
- 29. 8) 3D CADApplications The CAD (Computer-aided design) is used to design engineering related architecture. It is used to develop the 3D representation of a part of a system. Python can create a 3D CAD application by using the following functionalities. Fandango (Popular ) CAMVOX HeeksCNC AnyCAD RCAM 9) Enterprise Applications Python can be used to create applications that can be used within an Enterprise or an Organization. Some real-time applications are OpenERP, Tryton, Picalo, etc. 10) Image Processing Application Python contains many libraries that are used to work with the image. The image can be manipulated according to our requirements. Some libraries of image processing are given below. OpenCV Pillow SimpleITK
- 30. How to InstallPython • Installing Python on Windows: • Download Python: – Visit the official Python website at https://www.python.org/downloads/windows/. – Click on the "Downloads" tab. – Download the latest Python installer for Windows. Choose the installer that corresponds to your system architecture (32-bit or 64-bit). • Run the Installer: – Locate the downloaded installer file (e.g., python-3.x.x.exe) and double-click it to run the installer. • Customize Installation (Optional): – You can customize the installation by clicking the "Customize installation" button. However, the default settings are usually sufficient for most users. • Installation Options: – Make sure to check the box that says "Add Python X.X to PATH." This allows you to use Python from the command line without needing to specify the full path. • Installation: – Click the "Install Now" button to begin the installation process. • Completing the Installation: – Once the installation is complete, you should see a screen that says "Setup was successful." You can now close the installer. • Verify Installation: – Open the Command Prompt by searching for "cmd" in the Windows Start Menu. – Type python and press Enter. You should see the Python version information. This confirms that Python is installed.
- 31. • Installing Pythonon Ubuntu: • Open the Terminal: – Press Ctrl+Alt+T to open a terminal window. • Update Package List: – Before installing Python, it's a good practice to update the package list to ensure you're getting the latest version of Python and its dependencies. Run the following command: • sudo apt update • sudo apt install python3 • python3 --version • This should display the Python version installed.
- 32. First Python Program •In Python, the most basic program is one that prints a message to the screen. Here's a "Hello, World!" program: • print("Hello, World!") • Now, let's break it down: • 1. `print()`: `print` is a Python function used to output text or data to the console (the terminal or command prompt). In this case, it's used to print the message "Hello, World!" to the screen. • 2. `"Hello, World!"`: This is a string. In Python, strings are sequences of characters enclosed in either single (`'`) or double (`"`) quotes. In this case, we're using double quotes.
- 33. • So, whenyou run this Python program, it will simply display "Hello, World!" in the console. • Here's how you can run the program: 1. Save the code in a file with a `.py` extension, like `hello.py`. 2. Open a terminal or command prompt. 3. Navigate to the directory where you saved the `hello.py` file. 4. Run the program by typing `python hello.py` and pressing Enter. You should see the output: Hello, World!
- 34. Python Variables • Variableis a name that is used to refer to memory location. Python variable is also known as an identifier and used to hold value. • In Python, we don't need to specify the type of variable because Python is a infer language and smart enough to get variable type. • Variable names can be a group of both the letters and digits, but they have to begin with a letter or an underscore. • It is recommended to use lowercase letters for the variable name. Rahul and rahul both are two different variables.
- 35. Python Variables • Variableis a name that is used to refer to memory location. Python variable is also known as an identifier and used to hold value. • In Python, we don't need to specify the type of variable because Python is a infer language and smart enough to get variable type. • Variable names can be a group of both the letters and digits, but they have to begin with a letter or an underscore. • It is recommended to use lowercase letters for the variable name. Rahul and rahul both are two different variables.
- 36. Identifier Naming: • Variablesare the example of identifiers. An Identifier is used to identify the literals used in the program. The rules to name an identifier are given below. • The first character of the variable must be an alphabet or underscore ( _ ). • All the characters except the first character may be an alphabet of lower-case(a-z), upper-case (A-Z), underscore, or digit (0-9). • Identifier name must not contain any white-space, or special character (!, @, #, %, ^, &, *). • Identifier name must not be similar to any keyword defined in the language. • Identifier names are case sensitive; for example, my name, and MyName is not the same. • Examples of valid identifiers: a123, _n, n_9, etc. • Examples of invalid identifiers: 1a, n%4, n 9, etc.
- 37. Declaring Variable andAssigning Values • Python does not bind us to declare a variable before using it in the application. It allows us to create a variable at the required time. • We don't need to declare explicitly variable in Python. When we assign any value to the variable, that variable is declared automatically. • The equal (=) operator is used to assign value to a variable. • Object References • It is necessary to understand how the Python interpreter works when we declare a variable. The process of treating variables is somewhat different from many other programming languages. • Python is the highly object-oriented programming language; that's why every data item belongs to a specific type of class. Consider the following example.
- 38. print("John") Output: John • The Pythonobject creates an integer object and displays it to the console. In the above print statement, we have created a string object. Let's check the type of it using the Python built- in type() function. type("John") Output: <class 'str'> • In Python, variables are a symbolic name that is a reference or pointer to an object. The variables are used to denote objects by that name. • Let's understand the following example a = 50 • In the above image, the variable a refers to an integer object. • Suppose we assign the integer value 50 to a new variable b.
- 39. a = 50 b= a • The variable b refers to the same object that a points to because Python does not create another object. • Let's assign the new value to b. Now both variables will refer to the different objects. a = 50 b =100 • python manages memory efficiently if we assign the same variable to two different values.
- 40. Object Identity • InPython, every created object identifies uniquely in Python. Python provides the guaranteed that no two objects will have the same identifier. The built-in id() function, is used to identify the object identifier. Consider the following example. a = 50 b = a print(id(a)) print(id(b)) # Reassigned variable a a = 500 print(id(a)) Output: 140734982691168 140734982691168 2822056960944 • We assigned the b = a, a and b both point to the same object. When we checked by the id() function it returned the same number. We reassign a to 500; then it referred to the new object identifier.
- 41. Variable Names • Wehave already discussed how to declare the valid variable. Variable names can be any length can have uppercase, lowercase (A to Z, a to z), the digit (0-9), and underscore character(_). Consider the following example of valid variables names. name = "Devansh" age = 20 marks = 80.50 print(name) print(age) print(marks) Output: Devansh 20 80.5
- 42. • Consider thefollowing valid variables name. name = "A" Name = "B" naMe = "C" NAME = "D" n_a_m_e = "E" _name = "F" name_ = "G" _name_ = "H" na56me = "I" print(name,Name,naMe,NAME,n_a_m_e, NAME, n_a_m_e, _name, name_, _name, na56me) Output: A B C D E D E F G F I • In the above example, we have declared a few valid variable names such as name, _name_ , etc. But it is not recommended because when we try to read code, it may create confusion. The variable name should be descriptive to make code more readable.
- 43. • The multi-wordkeywords can be created by the following method. • Camel Case - In the camel case, each word or abbreviation in the middle of begins with a capital letter. There is no intervention of whitespace. For example - nameOfStudent, valueOfVaraible, etc. • Pascal Case - It is the same as the Camel Case, but here the first word is also capital. For example - NameOfStudent, etc. • Snake Case - In the snake case, Words are separated by the underscore. For example - name_of_student, etc.
- 44. Multiple Assignment • Pythonallows us to assign a value to multiple variables in a single statement, which is also known as multiple assignments. • We can apply multiple assignments in two ways, either by assigning a single value to multiple variables or assigning multiple values to multiple variables. Consider the following example. 1. Assigning single value to multiple variables Eg: x=y=z=50 print(x) print(y) print(z) Output: 50 50 50
- 45. 2. Assigning multiplevalues to multiple variables: Eg: a,b,c=5,10,15 print a print b print c Output: 5 10 15 • The values will be assigned in the order in which variables appear.
- 46. Python Variable Types •There are two types of variables in Python - Local variable and Global variable. Let's understand the following variables. Local Variable • Local variables are the variables that declared inside the function and have scope within the function. Let's understand the following example. Example - # Declaring a function def add(): # Defining local variables. They has scope only within a function a = 20 b = 30 c = a + b print("The sum is:", c) # Calling a function add() Output: The sum is: 50
- 47. Explanation: • In theabove code, we declared a function named add() and assigned a few variables within the function. These variables will be referred to as the local variables which have scope only inside the function. If we try to use them outside the function, we get a following error. add() # Accessing local variable outside the function print(a) • Output: The sum is: 50 print(a) NameError: name 'a' is not defined • We tried to use local variable outside their scope; it threw the NameError.
- 48. Global Variables • Globalvariables can be used throughout the program, and its scope is in the entire program. We can use global variables inside or outside the function. • A variable declared outside the function is the global variable by default. Python provides the global keyword to use global variable inside the function. If we don't use the global keyword, the function treats it as a local variable. Let's understand the following example. Example - # Declare a variable and initialize it x = 101
- 49. # Global variablein function def mainFunction(): # printing a global variable global x print(x) # modifying a global variable x = 'Welcome To Javatpoint' print(x) mainFunction() print(x) Output: 101 Welcome To Javatpoint Welcome To Javatpoint
- 50. Explanation: • In theabove code, we declare a global variable x and assign a value to it. Next, we defined a function and accessed the declared variable using the global keyword inside the function. Now we can modify its value. Then, we assigned a new string value to the variable x. • Now, we called the function and proceeded to print x. It printed the as newly assigned value of x.
- 51. Delete a variable: •We can delete the variable using the del keyword. The syntax is given below. • Syntax – • del <variable_name> • In the following example, we create a variable x and assign value to it. We deleted variable x, and print it, we get the error "variable x is not defined". The variable x will no longer use in future. Example - # Assigning a value to x x = 6 print(x) # deleting a variable. del x print(x) Output: 6 Traceback (most recent call last): File "C:/Users/DEVANSH SHARMA/PycharmProjects/Hello/multiprocessing.py", line 389, in print(x) NameError: name 'x' is not defined
- 52. Maximum Possible Valueof an Integer in Python • Unlike the other programming languages, Python doesn't have long int or float data types. It treats all integer values as an int data type. Here, the question arises. What is the maximum possible value can hold by the variable in Python? Consider the following example. • Example – # A Python program to display that we can store # large numbers in Python a = 10000000000000000000000000000000000000000000 a = a + 1 print(type(a)) print (a) Output: <class 'int'> 10000000000000000000000000000000000000000001 • As we can see in the above example, we assigned a large integer value to variable x and checked its type. It printed class <int> not long int. Hence, there is no limitation number by bits and we can expand to the limit of our memory. • Python doesn't have any special data type to store larger numbers.
- 53. Print Single andMultiple Variables in Python • We can print multiple variables within the single print statement. Below are the example of single and multiple printing values. Example - 1 (Printing Single Variable) # printing single value a = 5 print(a) print((a)) Output: 5 5 Example - 2 (Printing Multiple Variables) a = 5 b = 6 # printing multiple variables print(a,b) # separate the variables by the comma Print(1, 2, 3, 4, 5, 6, 7, 8) Output: 5 6 1 2 3 4 5 6 7 8
- 54. Basic Fundamentals: This sectioncontains the fundamentals of Python, such as: i)Tokens and their types. ii) Comments a)Tokens: • The tokens can be defined as a punctuator mark, reserved words, and each word in a statement. • The token is the smallest unit inside the given program. There are following tokens in Python: Keywords. Identifiers. Literals. Operators.
- 55. Python Data Types •Every value has a datatype, and variables can hold values. Python is a powerfully composed language; consequently, we don't have to characterize the sort of variable while announcing it. The interpreter binds the value implicitly to its type. a = 5 • We did not specify the type of the variable a, which has the value five from an integer. The Python interpreter will automatically interpret the variable as an integer. • We can verify the type of the program-used variable thanks to Python. The type() function in Python returns the type of the passed variable. • Consider the following illustration when defining and verifying the values of various data types.
- 56. Program: a=10 b="Hi Python" c =10.5 print(type(a)) print(type(b)) print(type(c)) Output: <type 'int'> <type 'str'> <type 'float'>
- 57. Standard data types: •A variable can contain a variety of values. On the other hand, a person's id must be stored as an integer, while their name must be stored as a string. • The storage method for each of the standard data types that Python provides is specified by Python. The following is a list of the Python-defined data types. Numbers Sequence Type Boolean Set Dictionary
- 59. • The datatypes will be briefly discussed in this tutorial section. We will talk about every single one of them exhaustively later in this instructional exercise. Numbers: • Numeric values are stored in numbers. The whole number, float, and complex qualities have a place with a Python Numbers datatype. Python offers the type() function to determine a variable's data type. The instance () capability is utilized to check whether an item has a place with a specific class. • When a number is assigned to a variable, Python generates Number objects. For instance,
- 60. Program: a = 5 print("Thetype of a", type(a)) b = 40.5 print("The type of b", type(b)) c = 1+3j print("The type of c", type(c)) print(" c is a complex number", isinstance(1+3j,complex) ) Output: The type of a <class 'int'> The type of b <class 'float'> The type of c <class 'complex'> c is complex number: True Python supports three kinds of numerical data.
- 61. • Int: Wholenumber worth can be any length, like numbers 10, 2, 29, - 20, - 150, and so on. An integer can be any length you want in Python. Its worth has a place with int. • Float: Float stores drifting point numbers like 1.9, 9.902, 15.2, etc. It can be accurate to within 15 decimal places. • Complex: An intricate number contains an arranged pair, i.e., x + iy, where x and y signify the genuine and non-existent parts separately. The complex numbers like 2.14j, 2.0 + 2.3j, etc.
- 62. Sequence Type String • Thesequence of characters in the quotation marks can be used to describe the string. A string can be defined in Python using single, double, or triple quotes. • String dealing with Python is a direct undertaking since Python gives worked-in capabilities and administrators to perform tasks in the string. • When dealing with strings, the operation "hello"+" python" returns "hello python," and the operator + is used to combine two strings. • Because the operation "Python" *2 returns "Python," the operator * is referred to as a repetition operator. • The Python string is demonstrated in the following example.
- 63. Example - 1 str= "string using double quotes" print(str) s = '''''A multiline string''' print(s) Output: string using double quotes A multiline string Look at the following illustration of string handling.
- 64. Example - 2 str1= 'hello javatpoint' #string str1 str2 = ' how are you' #string str2 print (str1[0:2]) #printing first two character using slice operator print (str1[4]) #printing 4th character of the string print (str1*2) #printing the string twice print (str1 + str2) #printing the concatenation of str1 a nd str2 Output: he o hello javatpointhello javatpoint hello javatpoint how are you
- 65. • List: • Listsin Python are like arrays in C, but lists can contain data of different types. The things put away in the rundown are isolated with a comma (,) and encased inside square sections []. • To gain access to the list's data, we can use slice [:] operators. Like how they worked with strings, the list is handled by the concatenation operator (+) and the repetition operator (*).
- 66. Example: list1 = [1,"hi", "Python", 2] #Checking type of given list print(type(list1)) #Printing the list1 print (list1) # List slicing print (list1[3:]) # List slicing print (list1[0:2]) # List Concatenation using + operator print (list1 + list1) # List repetation using * operator print (list1 * 3) Output: [1, 'hi', 'Python', 2] [2] [1, 'hi'] [1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2] [1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2, 1, 'hi', 'Python', 2]
- 67. Tuple: • In manyways, a tuple is like a list. Tuples, like lists, also contain a collection of items from various data types. A parenthetical space () separates the tuple's components from one another. • Because we cannot alter the size or value of the items in a tuple, it is a read-only data structure. • Let's look at a straightforward tuple in action.
- 68. Example: tup = ("hi","Python", 2) # Checking type of tup print (type(tup)) #Printing the tuple print (tup) # Tuple slicing print (tup[1:]) print (tup[0:1]) # Tuple concatenation using + operator print (tup + tup) # Tuple repatation using * operator print (tup * 3) # Adding value to tup. It will throw an error. t[2] = "hi"
- 69. Output: <class 'tuple'> ('hi', 'Python',2) ('Python', 2) ('hi',) ('hi', 'Python', 2, 'hi', 'Python', 2) ('hi', 'Python', 2, 'hi', 'Python', 2, 'hi', 'Python', 2) Traceback (most recent call last): File "main.py", line 14, in <module> t[2] = "hi"; TypeError: 'tuple' object does not support item assignment
- 70. Dictionary • A dictionaryis a key-value pair set arranged in any order. It stores a specific value for each key, like an associative array or a hash table. Value is any Python object, while the key can hold any primitive data type. • The comma (,) and the curly braces are used to separate the items in the dictionary. • Look at the following example. d = {1:'Jimmy', 2:'Alex', 3:'john', 4:'mike'} # Printing dictionary print (d) # Accesing value using keys print("1st name is "+d[1]) print("2nd name is "+ d[4]) print (d.keys()) print (d.values())
- 71. • Output: 1st nameis Jimmy 2nd name is mike {1: 'Jimmy', 2: 'Alex', 3: 'john', 4: 'mike'} dict_keys([1, 2, 3, 4]) dict_values(['Jimmy', 'Alex', 'john', 'mike'])
- 72. Boolean: • True andFalse are the two default values for the Boolean type. These qualities are utilized to decide the given assertion valid or misleading. The class book indicates this. False can be represented by the 0 or the letter "F," while true can be represented by any value that is not zero. Look at the following example. # Python program to check the boolean type print(type(True)) print(type(False)) print(false) Output: <class 'bool'> <class 'bool'> NameError: name 'false' is not defined
- 73. Set: • The datatype's unordered collection is Python Set. It is iterable, mutable(can change after creation), and has remarkable components. The elements of a set have no set order; It might return the element's altered sequence. Either a sequence of elements is passed through the curly braces and separated by a comma to create the set or the built-in function set() is used to create the set. It can contain different kinds of values. • Look at the following example.
- 74. Program: # Creating Emptyset set1 = set() set2 = {'James', 2, 3,'Python'} #Printing Set value print(set2) # Adding element to the set set2.add(10) print(set2) #Removing element from the set set2.remove(2) print(set2) Output: {3, 'Python', 'James', 2} {'Python', 'James', 3, 2, 10} {'Python', 'James', 3, 10}
- 75. Python Keywords • Everyscripting language has designated words or keywords, with particular definitions and usage guidelines. Python is no exception. The fundamental constituent elements of any Python program are Python keywords. • This tutorial will give you a basic overview of all Python keywords and a detailed discussion of some important keywords that are frequently used. Introducing Python Keywords: • Python keywords are unique words reserved with defined meanings and functions that we can only apply for those functions. You'll never need to import any keyword into your program because they're permanently present. • Python's built-in methods and classes are not the same as the keywords. Built-in methods and classes are constantly present; however, they are not as limited in their application as keywords.
- 76. • Assigning aparticular meaning to Python keywords means you can't use them for other purposes in our code. You'll get a message of SyntaxError if you attempt to do the same. If you attempt to assign anything to a built-in method or type, you will not receive a SyntaxError message; however, it is still not a smart idea. • Python contains thirty-five keywords in the most recent version, i.e., Python 3.8. Here we have shown a complete list of Python keywords for the reader's reference.
- 77. in distinct versionsof Python, the preceding keywords might be changed. Some extras may be introduced, while others may be deleted. By writing the following statement into the coding window, you can anytime retrieve the collection of keywords in the version you are working on.
- 78. Code: # Python programto demonstrate the application of iskeyword() # importing keyword library which has lists import keyword # displaying the complete list using "kwlist()." print("The set of keywords in this version is: ") print( keyword.kwlist ) Output: The set of keywords in this version is : ['False', 'None', 'True', 'and', 'as', 'assert', 'async', 'await', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield'] By calling help(), you can retrieve a list of currently offered keywords: Code help("keywords")
- 79. Python Literals Python Literalscan be defined as data that is given in a variable or constant. • Python supports the following literals: 1. String literals: • String literals can be formed by enclosing a text in the quotes. We can use both single as well as double quotes to create a string. Example: "Aman" , '12345'
- 80. Types of Strings: Thereare two types of Strings supported in Python: a) Single-line String- Strings that are terminated within a single-line are known as Single line Strings. Example: text1='hello' b) Multi-line String - A piece of text that is written in multiple lines is known as multiple lines string. There are two ways to create multiline strings: Adding black slash at the end of each line. Example: text1='hello user' print(text1) 'hellouser'
- 81. 2) Using triplequotation marks:- Example: str2='''''welcome to SSSIT''' print str2 Output: welcome to SSSIT II. Numeric literals: Numeric Literals are immutable. Numeric literals can belong to following four different numerical types.
- 82. Example - NumericLiterals x = 0b10100 #Binary Literals y = 100 #Decimal Literal z = 0o215 #Octal Literal u = 0x12d #Hexadecimal Literal #Float Literal float_1 = 100.5 float_2 = 1.5e2 #Complex Literal a = 5+3.14j print(x, y, z, u) print(float_1, float_2) print(a, a.imag, a.real)
- 83. Output: 20 100 141301 100.5 150.0 (5+3.14j) 3.14 5.0 III. Boolean literals: • A Boolean literal can have any of the two values: True or False. Example - Boolean Literals x = (1 == True) y = (2 == False) z = (3 == True) a = True + 10 b = False + 10 print("x is", x) print("y is", y) print("z is", z) print("a:", a) print("b:", b)
- 84. Output: x is True yis False z is False a: 11 b: 10 IV. Special literals: • Python contains one special literal i.e., None. • None is used to specify to that field that is not created. It is also used for the end of lists in Python. Example - Special Literals val1=10 val2=None print(val1) print(val2) Output: 10 None
- 85. V. Literal Collections. •Python provides the four types of literal collection such as List literals, Tuple literals, Dict literals, and Set literals. List: • List contains items of different data types. Lists are mutable i.e., modifiable. • The values stored in List are separated by comma(,) and enclosed within square brackets([]). We can store different types of data in a List.
- 86. Example - Listliterals list=['John',678,20.4,'Peter'] list1=[456,'Andrew'] print(list) print(list + list1) Output: ['John', 678, 20.4, 'Peter'] ['John', 678, 20.4, 'Peter', 456, 'Andrew'] • Dictionary: • Python dictionary stores the data in the key-value pair. • It is enclosed by curly-braces {} and each pair is separated by the commas(,).
- 87. Example dict = {'name':'Pater', 'Age':18,'Roll_nu':101} print(dict) Output: {'name': 'Pater', 'Age': 18, 'Roll_nu': 101} Tuple: Python tuple is a collection of different data-type. It is immutable which means it cannot be modified after creation. It is enclosed by the parentheses () and each element is separated by the comma(,). Example tup = (10,20,"Dev",[2,3,4]) print(tup) Output: (10, 20, 'Dev', [2, 3, 4])
- 88. Set: Python set isthe collection of the unordered dataset. It is enclosed by the {} and each element is separated by the comma(,). Example: - Set Literals set = {'apple','grapes','guava','papaya'} print(set) Output: {'guava', 'apple', 'papaya', 'grapes'}
- 89. Python Operators Introduction: • Theoperator is a symbol that performs a specific operation between two operands, according to one definition. Operators serve as the foundation upon which logic is constructed in a program in a particular programming language. In every programming language, some operators perform several tasks. Same as other languages, Python also has some operators, and these are given below – • Arithmetic operators • Comparison operators • Assignment Operators • Logical Operators • Bitwise Operators • Membership Operators • Identity Operators • Arithmetic Operators
- 90. Arithmetic Operators: • Arithmeticoperators used between two operands for a particular operation. There are many arithmetic operators. It includes the exponent (**) operator as well as the + (addition), - (subtraction), * (multiplication), / (divide), % (reminder), and // (floor division) operators. • Consider the following table for a detailed explanation of arithmetic operators.
- 92. Program Code: • Nowwe give code examples of arithmetic operators in Python. The code is given below - a = 32 # Initialize the value of a b = 6 # Initialize the value of b print('Addition of two numbers:',a+b) print('Subtraction of two numbers:',a-b) print('Multiplication of two numbers:',a*b) print('Division of two numbers:',a/b) print('Reminder of two numbers:',a%b) print('Exponent of two numbers:',a**b) print('Floor division of two numbers:',a//b)
- 93. • Output: • Nowwe compile the above code in Python, and after successful compilation, we run it. Then the output is given below - Addition of two numbers: 38 Subtraction of two numbers: 26 Multiplication of two numbers: 192 Division of two numbers: 5.333333333333333 Reminder of two numbers: 2 Exponent of two numbers: 1073741824 Floor division of two numbers: 5
- 94. • Comparison operator: •Comparison operators mainly use for comparison purposes. Comparison operators compare the values of the two operands and return a true or false Boolean value in accordance. The example of comparison operators are ==, !=, <=, >=, >, <. In the below table, we explain the works of the operators.
- 95. • Program Code: •Now we give code examples of Comparison operators in Python. The code is given below - a = 32 # Initialize the value of a b = 6 # Initialize the value of b print('Two numbers are equal or not:',a==b) print('Two numbers are not equal or not:',a!=b) print('a is less than or equal to b:',a<=b) print('a is greater than or equal to b:',a>=b) print('a is greater b:',a>b) print('a is less than b:',a<b)
- 96. • Output: • Nowwe compile the above code in Python, and after successful compilation, we run it. Then the output is given below - Two numbers are equal or not: False Two numbers are not equal or not: True a is less than or equal to b: False a is greater than or equal to b: True a is greater b: True a is less than b: False
- 97. • Assignment Operators: •Using the assignment operators, the right expression's value is assigned to the left operand. There are some examples of assignment operators like =, +=, -=, *=, %=, **=, //=. In the below table, we explain the works of the operators.
- 99. Program Code: Now wegive code examples of Assignment operators in Python. The code is given below - a = 32 # Initialize the value of a b = 6 # Initialize the value of b print('a=b:', a==b) print('a+=b:', a+b) print('a-=b:', a-b) print('a*=b:', a*b) print('a%=b:', a%b) print('a**=b:', a**b) print('a//=b:', a//b)
- 100. Output: • Now wecompile the above code in Python, and after successful compilation, we run it. Then the output is given below – a=b: False a+=b: 38 a-=b: 26 a*=b: 192 a%=b: 2 a**=b: 1073741824 a//=b: 5
- 101. Bitwise Operators: • Thetwo operands' values are processed bit by bit by the bitwise operators. The examples of Bitwise operators are bitwise OR (|), bitwise AND (&), bitwise XOR (^), negation (~), Left shift (<<), and Right shift (>>). Consider the case below. • For example, if a = 7 b = 6 then, binary (a) = 0111 binary (b) = 0110 hence, a & b = 0011 a | b = 0111 a ^ b = 0100 ~ a = 1000 Let, Binary of x = 0101 Binary of y = 1000 Bitwise OR = 1101 8 4 2 1 1 1 0 1 = 8 + 4 + 1 = 13 Bitwise AND = 0000 0000 = 0 Bitwise XOR = 1101 8 4 2 1 1 1 0 1 = 8 + 4 + 1 = 13 Negation of x = ~x = (-x) - 1 = (-5) - 1 = -6 ~x = -6
- 102. • In thebelow table, we are explaining the works of the bitwise operators.
- 103. Program Code: Now wegive code examples of Bitwise operators in Python. The code is given below - a = 5 # initialize the value of a b = 6 # initialize the value of b print('a&b:', a&b) print('a|b:', a|b) print('a^b:', a^b) print('~a:', ~a) print('a<<b:', a<<b) print('a>>b:', a>>b)
- 104. Output: Now we compilethe above code in Python, and after successful compilation, we run it. Then the output is given below - a&b: 4 a|b: 7 a^b: 3 ~a: -6 a<>b: 0
- 105. Logical Operators • Theassessment of expressions to make decisions typically uses logical operators. The examples of logical operators are and, or, and not. In the case of logical AND, if the first one is 0, it does not depend upon the second one. In the case of logical OR, if the first one is 1, it does not depend on the second one. Python supports the following logical operators. In the below table, we explain the works of the logical operators.
- 107. Program Code: Now wegive code examples of arithmetic operators in Python. The code is given below - a = 5 # initialize the value of a print(Is this statement true?:',a > 3 and a < 5) print('Any one statement is true?:',a > 3 or a < 5) print('Each statement is true then return False and vice- versa:',(not(a > 3 and a < 5))) Output: Now we give code examples of Bitwise operators in Python. The code is given below - Is this statement true?: False Any one statement is true?: True Each statement is true then return False and vice-versa: True
- 108. Membership Operators: • Themembership of a value inside a Python data structure can be verified using Python membership operators. The result is true if the value is in the data structure; otherwise, it returns false.
- 109. Program Code: Now wegive code examples of Membership operators in Python. The code is given below - x = ["Rose", "Lotus"] print(' Is value Present?', "Rose" in x) print(' Is value not Present?', "Riya" not in x) Output: Now we compile the above code in Python, and after successful compilation, we run it. Then the output is given below - Is value Present? True Is value not Present? True
- 110. Identity Operators Program Code: Nowwe give code examples of Identity operators in Python. The code is given below - a = ["Rose", "Lotus"] b = ["Rose", "Lotus"] c = a print(a is c) print(a is not c) print(a is b) print(a is not b) print(a == b) print(a != b)
- 111. Output: Now we compilethe above code in python, and after successful compilation, we run it. Then the output is given below - True False False True True False
- 112. Operator Precedence: • Theorder in which the operators are examined is crucial to understand since it tells us which operator needs to be considered first. Below is a list of the Python operators' precedence tables.
- 114. Python Comments • Introductionto Python Comments • We may wish to describe the code we develop. We might wish to take notes of why a section of script functions, for instance. We leverage the remarks to accomplish this. Formulas, procedures, and sophisticated business logic are typically explained with comments. The Python interpreter overlooks the remarks and solely interprets the script when running a program. Single-line comments, multi-line comments, and documentation strings are the 3 types of comments in Python. • Advantages of Using Comments • Our code is more comprehensible when we use comments in it. It assists us in recalling why specific sections of code were created by making the program more understandable. • Aside from that, we can leverage comments to overlook specific code while evaluating other code sections. This simple technique stops some lines from running or creates a fast pseudo-code for the program.
- 115. • Below aresome of the most common uses for comments: • Readability of the Code • Restrict code execution • Provide an overview of the program or project metadata • To add resources to the code • Types of Comments in Python • In Python, there are 3 types of comments. They are described below: • Single-Line Comments: • Single-line remarks in Python have shown to be effective for providing quick descriptions for parameters, function definitions, and expressions. A single-line comment of Python is the one that has a hashtag # at the beginning of it and continues until the finish of the line. If the comment continues to the next line, add a hashtag to the subsequent line and resume the conversation. Consider the accompanying code snippet, which shows how to use a single line comment:
- 116. Code # This codeis to show an example of a single-line comment print( 'This statement does not have a hashtag before it' ) Output: This statement does not have a hashtag before it The following is the comment: • # This code is to show an example of a single-line comment The Python compiler ignores this line. • Everything following the # is omitted. As a result, we may put the program mentioned above in one line as follows: Code print( 'This is not a comment' ) # this code is to show an example o f a single-line comment Output: This is not a comment • This program's output will be identical to the example above. The computer overlooks all content following #.
- 117. • Multi-Line Comments: •Python does not provide the facility for multi-line comments. However, there are indeed many ways to create multi-line comments. • With Multiple Hashtags (#) • In Python, we may use hashtags (#) multiple times to construct multiple lines of comments. Every line with a (#) before it will be regarded as a single-line comment. Code: # it is a # comment # extending to multiple lines • In this case, each line is considered a comment, and they are all omitted.
- 118. • Using StringLiterals: • Because Python overlooks string expressions that aren't allocated to a variable, we can utilize them as comments. Code: 'it is a comment extending to multiple lines' • We can observe that on running this code, there will be no output; thus, we utilize the strings inside triple quotes(""") as multi-line comments. Python Docstring: • The strings enclosed in triple quotes that come immediately after the defined function are called Python docstring. It's designed to link documentation developed for Python modules, methods, classes, and functions together. It's placed just beneath the function, module, or class to explain what they perform. The docstring is then readily accessible in Python using the __doc__ attribute.
- 119. Code: # Code toshow how we use docstrings in Python def add(x, y): """This function adds the values of x and y""" return x + y # Displaying the docstring of the add function print( add.__doc__ ) Output: This function adds the values of x and y
- 120. Python If-else statements •Decision making is the most important aspect of almost all the programming languages. As the name implies, decision making allows us to run a particular block of code for a particular decision. Here, the decisions are made on the validity of the particular conditions. Condition checking is the backbone of decision making. • In python, decision making is performed by the following statements.
- 122. Indentation in Python •For the ease of programming and to achieve simplicity, python doesn't allow the use of parentheses for the block level code. In Python, indentation is used to declare a block. If two statements are at the same indentation level, then they are the part of the same block. • Generally, four spaces are given to indent the statements which are a typical amount of indentation in python. • Indentation is the most used part of the python language since it declares the block of code. All the statements of one block are intended at the same level indentation. We will see how the actual indentation takes place in decision making and other stuff in python.
- 123. The if statement: •The if statement is used to test a particular condition and if the condition is true, it executes a block of code known as if-block. The condition of if statement can be any valid logical expression which can be either evaluated to true or false.
- 125. The syntax ofthe if-statement is given below. if expression: statement Example 1: # Simple Python program to understand the if statement num = int(input("enter the number:")) # Here, we are taking an integer num and taking input dyna mically if num%2 == 0: # Here, we are checking the condition. If the condition is true , we will enter the block print("The Given number is an even number") Output: enter the number: 10 The Given number is an even number
- 126. Example 2 :Program to print the largest of the three numbers. # Simple Python Program to print the largest of the three numbers. a = int (input("Enter a: ")); b = int (input("Enter b: ")); c = int (input("Enter c: ")); if a>b and a>c: # Here, we are checking the condition. If the condition is true, we will enter the bl ock print ("From the above three numbers given a is largest"); if b>a and b>c: # Here, we are checking the condition. If the condition is true, we will enter the bl ock print ("From the above three numbers given b is largest"); if c>a and c>b: # Here, we are checking the condition. If the condition is true, we will enter the bl ock print ("From the above three numbers given c is largest"); Output: Enter a: 100 Enter b: 120 Enter c: 130 From the above three numbers given c is largest
- 127. The if-else statement •The if-else statement provides an else block combined with the if statement which is executed in the false case of the condition • If the condition is true, then the if-block is executed. Otherwise, the else-block is executed. The syntax of the if-else statement is given below. if condition: #block of statements else: #another block of statements (else-block)
- 129. Example 1 :Program to check whether a person is eligible to vote or not. # Simple Python Program to check whether a person is eligible t o vote or not. age = int (input("Enter your age: ")) # Here, we are taking an integer num and taking input dynamica lly if age>=18: # Here, we are checking the condition. If the condition is true, w e will enter the block print("You are eligible to vote !!"); else: print("Sorry! you have to wait !!"); Output: Enter your age: 90 You are eligible to vote !!
- 130. Example 2: Programto check whether a number is even or not. # Simple Python Program to check whether a number is even or not. num = int(input("enter the number:")) # Here, we are taking an integer num and taking input dynamica lly if num%2 == 0: # Here, we are checking the condition. If the condition is true, w e will enter the block print("The Given number is an even number") else: print("The Given Number is an odd number") Output: enter the number: 10 The Given number is even number
- 131. The elif statement •The elif statement enables us to check multiple conditions and execute the specific block of statements depending upon the true condition among them. We can have any number of elif statements in our program depending upon our need. However, using elif is optional. • The elif statement works like an if-else-if ladder statement in C. It must be succeeded by an if statement. • The syntax of the elif statement is given below.
- 132. if expression 1: #block of statements elif expression 2: # block of statements elif expression 3: # block of statements else: # block of statements
- 134. Example 1 # SimplePython program to understand elif statement number = int(input("Enter the number?")) # Here, we are taking an integer number and taking input dynamically if number==10: # Here, we are checking the condition. If the condition is true, we will enter th e block print("The given number is equals to 10") elif number==50: # Here, we are checking the condition. If the condition is true, we will enter th e block print("The given number is equal to 50"); elif number==100: # Here, we are checking the condition. If the condition is true, we will enter th e block print("The given number is equal to 100"); else: print("The given number is not equal to 10, 50 or 100");
- 135. Output: Enter the number?15 Thegiven number is not equal to 10, 50 or 100
- 136. Example 2 # SimplePython program to understand elif statement marks = int(input("Enter the marks? ")) # Here, we are taking an integer marks and taking input dynamically if marks > 85 and marks <= 100: # Here, we are checking the condition. If the condition is true, we will enter the bloc k print("Congrats ! you scored grade A ...") elif marks > 60 and marks <= 85: # Here, we are checking the condition. If the condition is true, we will enter the bloc k print("You scored grade B + ...") elif marks > 40 and marks <= 60: # Here, we are checking the condition. If the condition is true, we will enter the bloc k print("You scored grade B ...") elif (marks > 30 and marks <= 40): # Here, we are checking the condition. If the condition is true, we will enter the bloc k print("You scored grade C ...") else: print("Sorry you are fail ?")
- 137. Output: Enter the marks?89 Congrats ! you scored grade A ...
- 138. Python Loops • Thefollowing loops are available in Python to fulfil the looping needs. Python offers 3 choices for running the loops. The basic functionality of all the techniques is the same, although the syntax and the amount of time required for checking the condition differ. • We can run a single statement or set of statements repeatedly using a loop command. • The following sorts of loops are available in the Python programming language.
- 140. • Loop ControlStatements: • Statements used to control loops and change the course of iteration are called control statements. All the objects produced within the local scope of the loop are deleted when execution is completed. • Python provides the following control statements. We will discuss them later in detail. • Let us quickly go over the definitions of these loop control statements.
- 142. The for Loop •Python's for loop is designed to repeatedly execute a code block while iterating through a list, tuple, dictionary, or other iterable objects of Python. The process of traversing a sequence is known as iteration. Syntax of the for Loop for value in sequence: { code block } • In this case, the variable value is used to hold the value of every item present in the sequence before the iteration begins until this particular iteration is completed. • Loop iterates until the final item of the sequence are reached.
- 143. Code: # Python programto show how the for loop works # Creating a sequence which is a tuple of numbers numbers = [4, 2, 6, 7, 3, 5, 8, 10, 6, 1, 9, 2] # variable to store the square of the number square = 0 # Creating an empty list squares = [] # Creating a for loop for value in numbers: square = value ** 2 squares.append(square) print("The list of squares is", squares) Output: The list of squares is [16, 4, 36, 49, 9, 25, 64, 100, 36, 1, 81, 4]
- 144. Using else Statementwith for Loop: As already said, a for loop executes the code block until the sequence element is reached. The statement is written right after the for loop is executed after the execution of the for loop is complete. Only if the execution is complete does the else statement comes into play. It won't be executed if we exit the loop or if an error is thrown. Here is a code to better understand if-else statements.
- 145. Code: # Python programto show how if- else statements work string = "Python Loop" # Initiating a loop for s in a string: # giving a condition in if block if s == "o": print("If block") # if condition is not satisfied then else block will be e xecuted else: print(s)
- 146.
- 147. Now similarly, usingelse with for loop. Syntax: for value in sequence: # executes the statements until sequences ar e exhausted else: # executes these statements when for loop is completed
- 148. Code: # Python programto show how to use else statement with fo r loop # Creating a sequence tuple_ = (3, 4, 6, 8, 9, 2, 3, 8, 9, 7) # Initiating the loop for value in tuple_: if value % 2 != 0: print(value) # giving an else statement else: print("These are the odd numbers present in the tuple")
- 149. Output: 3 9 3 9 7 These arethe odd numbers present in the tuple
- 150. The range() Function Withthe help of the range() function, we may produce a series of numbers. range(10) will produce values between 0 and 9. (10 numbers). We can give specific start, stop, and step size values in the manner range(start, stop, step size). If the step size is not specified, it defaults to 1. Since it doesn't create every value it "contains" after we construct it, the range object can be characterized as being "slow." It does provide in, len, and __getitem__ actions, but it is not an iterator. The example that follows will make this clear.
- 151. Code: # Python programto show the working of range() functio n print(range(15)) print(list(range(15))) print(list(range(4, 9))) print(list(range(5, 25, 4))) Output: range(0, 15) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14] [4, 5, 6, 7, 8] [5, 9, 13, 17, 21] • To iterate through a sequence of items, we can apply the range() method in for loops. We can use indexing to iterate through the given sequence by combining it with an iterable's len() function. Here's an illustration.
- 152. Code: # Python programto iterate over a sequence with the hel p of indexing tuple_ = ("Python", "Loops", "Sequence", "Condition", "R ange") # iterating over tuple_ using range() function for iterator in range(len(tuple_)): print(tuple_[iterator].upper()) Output: PYTHON LOOPS SEQUENCE CONDITION RANGE
- 153. While Loop • Whileloops are used in Python to iterate until a specified condition is met. However, the statement in the program that follows the while loop is executed once the condition changes to false. Syntax of the while loop is: while <condition>: { code block } • All the coding statements that follow a structural command define a code block. These statements are intended with the same number of spaces. Python groups statements together with indentation.
- 154. Code # Python programto show how to use a while loop counter = 0 # Initiating the loop while counter < 10: # giving the condition counter = counter + 3 print("Python Loops") Output: Python Loops Python Loops Python Loops Python Loops
- 155. Using else Statementwith while Loops As discussed earlier in the for loop section, we can use the else statement with the while loop also. It has the same syntax. Code #Python program to show how to use else statement with th e while loop counter = 0 # Iterating through the while loop while (counter < 10): counter = counter + 3 print("Python Loops") # Executed untile condition is met # Once the condition of while loop gives False this statement will be executed else: print("Code block inside the else statement")
- 156. Output: Python Loops Python Loops PythonLoops Python Loops Code block inside the else statement Single statement while Block: The loop can be declared in a single statement, as seen below. This is similar to the if-else block, where we can write the code block in a single line. Code: # Python program to show how to write a single statem ent while loop counter = 0 while (count < 3): print("Python Loops")
- 157. Loop Control Statements Nowwe will discuss the loop control statements in detail. We will see an example of each control statement. Continue Statement: It returns the control to the beginning of the loop. Code: # Python program to show how the continue statement work s # Initiating the loop for string in "Python Loops": if string == "o" or string == "p" or string == "t": continue print('Current Letter:', string)
- 158. Output: Current Letter: P CurrentLetter: y Current Letter: h Current Letter: n Current Letter: Current Letter: L Current Letter: s
- 159. Break Statement: It stopsthe execution of the loop when the break statement is reached. Code: # Python program to show how the break statement works # Initiating the loop for string in "Python Loops": if string == 'L': break print('Current Letter: ', string)
- 160. Output: Current Letter: P CurrentLetter: y Current Letter: t Current Letter: h Current Letter: o Current Letter: n Current Letter:
- 161. Pass Statement: Pass statementsare used to create empty loops. Pass statement is also employed for classes, functions, and empty control statements. Code: # Python program to show how the pass statement works for a string in "Python Loops": pass print( 'Last Letter:', string) Output: Last Letter: s
- 162. Python Functions • Acollection of related assertions that carry out a mathematical, analytical, or evaluative operation is known as a function. An assortment of proclamations called Python Capabilities returns the specific errand. Python functions are necessary for intermediate-level programming and are easy to define. Function names meet the same standards as variable names do. The objective is to define a function and group-specific frequently performed actions. Instead of repeatedly creating the same code block for various input variables, we can call the function and reuse the code it contains with different variables. • Client-characterized and worked-in capabilities are the two primary classes of capabilities in Python. It aids in maintaining the program's uniqueness, conciseness, and structure.
- 163. • Advantages ofPython Functions • Pause We can stop a program from repeatedly using the same code block by including functions. • Once defined, Python functions can be called multiple times and from any location in a program. • Our Python program can be broken up into numerous, easy-to-follow functions if it is significant. • The ability to return as many outputs as we want using a variety of arguments is one of Python's most significant achievements. • However, Python programs have always incurred overhead when calling functions. • However, calling functions has always been overhead in a Python program.
- 164. Syntax: # An examplePython Function def function_name( parameters ): # code block The accompanying components make up to characterize a capability, as seen previously. • The start of a capability header is shown by a catchphrase called def. • function_name is the function's name, which we can use to distinguish it from other functions. We will utilize this name to call the capability later in the program. Name functions in Python must adhere to the same guidelines as naming variables. • Using parameters, we provide the defined function with arguments. Notwithstanding, they are discretionary. • A colon (:) marks the function header's end. • We can utilize a documentation string called docstring in the short structure to make sense of the reason for the capability. • Several valid Python statements make up the function's body. The entire code block's indentation depth-typically four spaces-must be the same. • A return expression can get a value from a defined function.
- 165. • Illustration ofa User-Defined Function • We will define a function that returns the argument number's square when called. # Example Python Code for User-Defined function def square( num ): """ This function computes the square of the number. """ return num**2 object_ = square(6) print( "The square of the given number is: ", object_ ) Output: The square of the given number is: 36
- 166. • Calling aFunction: • Calling a Function To define a function, use the def keyword to give it a name, specify the arguments it must receive, and organize the code block. • When the fundamental framework for a function is finished, we can call it from anywhere in the program. An illustration of how to use the a_function function can be found below. # Example Python Code for calling a function # Defining a function def a_function( string ): "This prints the value of length of string" return len(string) # Calling the function we defined print( "Length of the string Functions is: ", a_function( "Functions" ) ) print( "Length of the string Python is: ", a_function( "Python" ) ) Output: Length of the string Functions is: 9 Length of the string Python is: 6
- 167. Pass by Referencevs. Pass by Value: In the Python programming language, all parameters are passed by reference. It shows that if we modify the worth of contention within a capability, the calling capability will similarly mirror the change. For instance, Code # Example Python Code for Pass by Reference vs. Value # defining the function def square( item_list ): '''''''This function will find the square of items in the list''' squares = [ ] for l in item_list: squares.append( l**2 ) return squares # calling the defined function my_list = [17, 52, 8]; my_result = square( my_list ) print( "Squares of the list are: ", my_result ) Output: Squares of the list are: [289, 2704, 64]
- 168. Function Arguments The followingare the types of arguments that we can use to call a function: 1. Default arguments 2. Keyword arguments 3. Required arguments 4. Variable-length arguments 1) Default Arguments: • A default contention is a boundary that takes as information a default esteem, assuming that no worth is provided for the contention when the capability is called. The following example demonstrates default arguments.
- 169. Code: # Python codeto demonstrate the use of default argum ents # defining a function def function( n1, n2 = 20 ): print("number 1 is: ", n1) print("number 2 is: ", n2) # Calling the function and passing only one argument print( "Passing only one argument" ) function(30) # Now giving two arguments to the function print( "Passing two arguments" ) function(50,30)
- 170. Output: Passing only oneargument number 1 is: 30 number 2 is: 20 Passing two arguments number 1 is: 50 number 2 is: 30
- 171. • Keyword Arguments •Keyword arguments are linked to the arguments of a called function. While summoning a capability with watchword contentions, the client might tell whose boundary esteem it is by looking at the boundary name. • We can eliminate or orchestrate specific contentions in an alternate request since the Python translator will interface the furnished watchwords to connect the qualities with its boundaries. One more method for utilizing watchwords to summon the capability() strategy is as per the following:
- 172. Code: # Python codeto demonstrate the use of keyword arguments # Defining a function def function( n1, n2 ): print("number 1 is: ", n1) print("number 2 is: ", n2) # Calling function and passing arguments without using keyword print( "Without using keyword" ) function( 50, 30) # Calling function and passing arguments using keyword print( "With using keyword" ) function( n2 = 50, n1 = 30)
- 173. Output: Without using keyword number1 is: 50 number 2 is: 30 With using keyword number 1 is: 30 number 2 is: 50
- 174. • 3) RequiredArguments • Required arguments are those supplied to a function during its call in a predetermined positional sequence. The number of arguments required in the method call must be the same as those provided in the function's definition. • We should send two contentions to the capability() all put together; it will return a language structure blunder, as seen beneath.
- 175. Code: # Python codeto demonstrate the use of default arguments # Defining a function def function( n1, n2 ): print("number 1 is: ", n1) print("number 2 is: ", n2) # Calling function and passing two arguments out of order, we need num1 to be 20 and num2 to be 30 print( "Passing out of order arguments" ) function( 30, 20 ) # Calling function and passing only one argument print( "Passing only one argument" ) try: function( 30 ) except: print( "Function needs two positional arguments" )
- 176. Output: Passing out oforder arguments number 1 is: 30 number 2 is: 20 Passing only one argument Function needs two positional arguments
- 177. 4) Variable-Length Arguments: •We can involve unique characters in Python capabilities to pass many contentions. However, we need a capability. This can be accomplished with one of two types of characters: • "args" and "kwargs" refer to arguments not based on keywords. • To help you understand arguments of variable length, here's an example.
- 178. Code: # Python codeto demonstrate the use of variable-length arguments # Defining a function def function( *args_list ): ans = [] for l in args_list: ans.append( l.upper() ) return ans # Passing args arguments object = function('Python', 'Functions', 'tutorial') print( object ) # defining a function def function( **kargs_list ): ans = [] for key, value in kargs_list.items(): ans.append([key, value]) return ans # Paasing kwargs arguments object = function(First = "Python", Second = "Functions", Third = "Tutorial") print(object)
- 179. Output: ['PYTHON', 'FUNCTIONS', 'TUTORIAL'] [['First','Python'], ['Second', 'Functions'], ['Third', 'Tutorial']]
- 180. return Statement: • Whena defined function is called, a return statement is written to exit the function and return the calculated value. Syntax: return < expression to be returned as output > • The return statement can be an argument, a statement, or a value, and it is provided as output when a particular job or function is finished. A declared function will return an empty string if no return statement is written. • A return statement in Python functions is depicted in the following example.
- 181. Code: # Python codeto demonstrate the use of return statements # Defining a function with return statement def square( num ): return num**2 # Calling function and passing arguments. print( "With return statement" ) print( square( 52 ) ) # Defining a function without return statement def square( num ): num**2 # Calling function and passing arguments. print( "Without return statement" ) print( square( 52 ) )
- 182. • Output: With returnstatement 2704 Without return statement None
- 183. Standard Type builtin functions • Python provides a wide range of built-in functions to work with standard data types. Here are some of the commonly used built-in functions for various standard data types: 1. Numeric Types: • int(): Converts a value to an integer. • float(): Converts a value to a floating-point number. • abs(): Returns the absolute value of a number. • round(): Rounds a floating-point number to the nearest integer.
- 184. • 2. Strings: •str(): Converts a value to a string. • len(): Returns the length of a string. • upper(): Converts a string to uppercase. • lower(): Converts a string to lowercase. • strip(): Removes leading and trailing whitespace from a string. • split(): Splits a string into a list of substrings based on a delimiter. • join(): Joins a list of strings into a single string using a delimiter. • find(): Searches for a substring within a string and returns its index. • replace(): Replaces occurrences of a substring in a string with another substring.
- 185. • 3. Lists: •list(): Converts an iterable (e.g., tuple, string) to a list. • len(): Returns the number of elements in a list. • append(): Adds an element to the end of a list. • extend(): Appends the elements of an iterable to a list. • insert(): Inserts an element at a specific index in a list. • remove(): Removes the first occurrence of a specified value from a list. • pop(): Removes and returns an element at a specified index. • index(): Returns the index of the first occurrence of a specified value. • count(): Returns the number of occurrences of a specified value in a list. • sort(): Sorts the elements of a list in ascending order. • reverse(): Reverses the order of elements in a list.
- 186. • 4. Tuples: •tuple(): Converts an iterable (e.g., list, string) to a tuple. • len(): Returns the number of elements in a tuple. • index(): Returns the index of the first occurrence of a specified value. • count(): Returns the number of occurrences of a specified value in a tuple. • 5. Dictionaries: • dict(): Creates a new dictionary or converts an iterable of key-value pairs to a dictionary. • len(): Returns the number of key-value pairs in a dictionary. • keys(): Returns a list of keys in the dictionary. • values(): Returns a list of values in the dictionary. • items(): Returns a list of key-value pairs as tuples. • get(): Returns the value associated with a key, or a default value if the key is not found. • pop(): Removes and returns the value associated with a key. • update(): Updates a dictionary with key-value pairs from another dictionary.
- 187. Unsupported types inpython Following are some of the types that are not supported by python Charcter type (char): In python there is no character data type, in python character is a string of length one, it is represented by class str. Pointers: No, we don't have any kind of Pointer in Python language. In C and C++, a pointer is a variable that holds a memory address, but we don't have any kind of Pointer in Python , if you want to find address of any object then you need to use id() function. Program: a=10 print(id(a)) #id() function is used to find address output: 9789280 long int and short int: In c programming for long size integer values and short size integer values we use long int data type and short int data type but python do not support long int and short int , in python for both long and short size integers we use type int. double data type: We use double data type for long size float values ,but python do not support double type. In python even for long size float values you can use float data type.python float is actually C’s double data type
- 188. lambda function A lambdafunction is a small anonymous function. A lambda function can take any number of arguments, but can only have one expression. Syntax lambda arguments : expression The expression is executed and the result is returned: Example Add 10 to argument a, and return the result: x = lambda a: a + 10 print(x(5)) output: 15 •
- 189. Python Function Recursion: Pythonalso accepts function recursion, which means a defined function can call itself. Function which calls itself is know as recursion. This has the benefit of meaning that you can loop through data to reach a result. Example: def name(): print(“my name is nagendra”) name() name() name()
- 190. output: my name isnagendra my name is nagendra my name is nagendra my name is nagendra : : : • in above example I written name() function inside name() function, which means function name() calls itself , so it keep on repeating same code again and again, so we can loop statements by using recursion
- 191. Following is anexample of a recursive function to find the factorial of an integer. • Factorial of a number is the product of all the integers from 1 to that number. For example, the factorial of 6 (denoted as 6!) is 1*2*3*4*5*6= 720 Example of a recursive function def factorial(n): if n == 1: return 1 else: return n * factorial(n-1) n = 5 print("The factorial of", n, "is", factorial(n)) output: The factorial of 5 is 120
- 192. Built-In Functions Python hasa set of built-in functions. input() Input() Python built-in functions, reads an input. Example: a=int(input(“enter no:”)) print(a) output: enter no: 10 10 eval() Eval( ) function will accept any data type values that you enter. Example: a=eval(input(“enter no:”)) print(a) output: enter no: 10 10
- 193. exec() exec() runs Pythoncode dynamically. >>> exec('a=2;b=3;print(a+b)') Output 5 hex() Hex() Python built-in functions, converts an integer to hexadecimal. >>> hex(16) Output ‘0x10’ id() id() returns an object’s identity(address). >>> id(orange) Output 100218832
- 194. len() We’ve seen len()so many times by now. It returns the length of an object. Example: a=(1,2,3,4,5,6,7) print(len(a)) output: 7 max() max() returns the item, in a sequence, with the highest value of all. Example: a=(1,2,3,4,5,6,7) print(max(a)) output: 7 min() min() returns the item, in a sequence, with the smallest value of all. Example: a=(1,2,3,4,5,6,7) print(min(a)) output: 1
- 195. pow() pow() takes twoarguments- say, x and y. It then returns the value of x to the power of y. >>> pow(3,4) Output 81 print() We don’t think we need to explain this anymore. We’ve been seeing this function since the beginning. >>> print("hi”) output: hi repr() repr() returns a representable string of an object. >>> repr("Hello") Output “‘Hello'”
- 196. range() we use range( ) function in order to print values in sequence example: >>> for i in range(1,6): print(i) Output 1 2 3 4 5 sorted() Like we’ve seen before, sorted() prints out a sorted version of an iterable. It does not, however, alter the iterable. >>> sorted('Python') Output [‘P’, ‘h’, ‘n’, ‘o’, ‘t’, ‘y’] sum() The function sum() takes an iterable as an argument, and returns the sum of all values. >>> sum([3,4,5],3) Output 15
- 197. type() We have beenseeing the type() function to check the type of object we’re dealing with. >>> type(10) Output <class ‘int’>
- 198. other built infunctions : int(), float(), str(), complex( ), list ( ) , tuple ( ) , set ( ) . • print(int(10.5)) #converting float value to int print(int("10")) #converting string to int • print(float(10)) #converting int to float print(float("10.5")) #converting string to float print(str(10)) #converting int to str • print(str(10.5)) #converting float to str • print(complex(1,2.3))#converting int and float numbers to complex print(list((1,2.4,"btech"))) #converting tuple to list print(tuple([1,2.4,"btech"])) #converting list to tuple print(set([1,2.4,"btech"])) #converting list to set
- 199. output: 10 10 10.0 10.5 10 10.5 (1+2.3j) [1, 2.4,'btech'] (1, 2.4, 'btech') {'btech', 1, 2.4}
- 200. Python object • Pythonis an object-oriented programming language. Everything is in Python treated as an object, including variable, function, list, tuple, dictionary, set, etc. Every object belongs to its class. For example - An integer variable belongs to integer class. An object is a real-life entity. An object is the collection of various data and functions that operate on those data. An object contains the following properties.
- 201. Value: data item thatis represented by an object Example: a=10 #here 10 is value print(a) output: 10 Type: an object’s type indicates what kind of values an object can hold. what operations can be applied to such objects. type ( ) function is used to find type of object Example: a=10 print(type(a)) output: <class ‘int’>
- 202. Identity : Each objectcontains unique identity that differentiates from all other objects. And you can check id of an object by using id ( ) function. Example: a=10 print(id(a)) output: 9789280
- 203. literals and typesof literal constants literal is a raw data given to variable or constant in python there are various types of literals they are numberic literals : 3 types – integer, float, complex Example: a=10 b=10.5 c=1+2j print(a) print(b) print(c) output: 10 10.5 1+2j
- 204. string literals : Example: a=”hello” print(a) output: Hello specialliterals : None if you dont want to give any value to the variable then you can use None Example: a=None print(a) output: here you will not get any output because None means nothing
- 205. python - Typeconversion • type conversion is the process of converting data of one type to another. For example: converting integer data to string. There are two types of type conversion in Python. Implicit Conversion - automatic type conversion Explicit Conversion - manual type conversion
- 206. Implicit Type Conversion: •In certain situations, Python automatically converts one data type to another. This is known as implicit type conversion. • Python always converts smaller data types to larger data types to avoid the loss of data. • Integer is smaller than float and float is smaller than string Example: a=10 b=10.5 c=a+b print(c) output: 20.5
- 207. • In theabove example, I took a value as 10 which is integer and b value as 10.5 which is float .though i given one value as integer and other value as float , i got output as float value because Python always converts smaller data types to larger data types to avoid the loss of data. In this example integer value is smaller than float value, so integer value 10 is automatically converted into float value,so i got output 20.5 which is float value.
- 208. Explicit Type Conversion: •In Explicit Type Conversion, Python cannot automatically converts one data type to another so, users converts one data type to another manually . • We use the built-in functions like int(), float(), str(), complex( ), list ( ) , tuple ( ) , set ( ) to perform explicit type conversion. • This type of conversion is also called typecasting because the user casts (changes) the data type of the objects.
- 209. Example: • print(int(10.5)) #convertingfloat value to int print(int("10")) #converting string to int • print(float(10)) #converting int to float print(float("10.5")) #converting string to float print(str(10)) #converting int to str • print(str(10.5)) #converting float to str • print(complex(1,2.3))#converting int and float numbers to complex print(list((1,2.4,"btech"))) #converting tuple to list print(tuple([1,2.4,"btech"])) #converting list to tuple print(set([1,2.4,"btech"])) #converting list to set
- 210. output: 10 10 10.0 10.5 10 10.5 (1+2.3j) [1, 2.4,'btech'] (1, 2.4, 'btech') {'btech', 1, 2.4}
- 211. explicit type conversionprogram 2: Example: a=10 b=”10” #when you take 10 in double quotes then it is string c=a+b print(c) output: error In above example it will display error because we cannot add integer value and string value So you need to convert string “10” to integer value by using int( ) function. Example: a=10 b="10” #when you take 10 in double quotes then it is string c=a+int(b) # now i converted string 10 to integer value by using int( ) print(c) output: 20
- 212. Python - Internaltypes Traceback: when you get an error it is recommended that you should trace it backward(traceback). Whenever the code gets an exception(error), the traceback will give the information about what went wrong in the code.The Python traceback contains great information that can help you find what is going wrong in the code. Example: a = [1, 2, 3] print(a[10]) output:. Traceback (most recent call last): File "", line 2, in print(a[10]) IndexError: list index out of range In above example, we are trying to access the 10th element of the list. With only 3 elements present in the list it will give Runtime error. When this program is executed you will get the above traceback.
- 213. Slice: • A sliceobject is used to specify how to slice a sequence. You can specify where to start the slicing, and where to end. You can also specify the step • The slice() function returns a slice object. Syntax slice(start, end, step) Example: a = ("a", "b", "c", "d", "e", "f", "g", "h") x = slice(3, 5) print(a[x]) output: ('d', 'e')
- 214. Xrange(): • Xrange objectsare created by xrange( ) function. In python3 there is no xrange ( ) function so, range ( ) function behaves like xrange( ) function. • • xrange() – This function returns the generator object that can be used to display numbers only by looping. • • To loop through a set of code a specified number of times, we can use the range() function, • • The range() function returns a sequence of numbers, starting from 0 by default, and increments by 1 (by default), and ends at a specified number.
- 215. Example: for x inrange(1,6): print(x) output: 1 2 3 4 5
- 216. code: • Code objectsare executable pieces of python source that are byte compiled, usually as return values form calling the compile ( ) . such objects are appropriate for execution by either exec( ) or by the eval( ). • Code objects themselves do not contain any information regarding their execution environment, but they are at the heart of every user-defined function, all of which do contain some execution context. frame: • These are objects representing execution stack frames in python • Frame objects contain all the information the python interpreter needs to know during a runtime execution environment. Each function call results in a new frame object , and for each frame object, a C stack frame is created.
- 217. ellipsis: • you canuse the ellipsis to indicate that you’re leaving something out. Essentially, you use three dots (...) .it is same like pass statement. Program: def fun(): ... fun() When you run above program There’s no error when you execute a • function in Python that contains only( ...) in the function body. That means you can use an ellipsis as a placeholder similar to the pass keyword
- 218. Other built intypes Type Null object ( None ) File Set Function / Method Module Class
- 219. Scope and Lifetimeof Variables • A variable's scope refers to the program's domain wherever it is declared. A capability's contentions and factors are not external to the characterized capability. They only have a local domain as a result. • The length of time a variable remains in RAM is its lifespan. The lifespan of a function is the same as the lifespan of its internal variables. When we exit the function, they are taken away from us. As a result, the value of a variable in a function does not persist from previous executions. • An easy illustration of a function's scope for a variable can be found here.
- 220. Code: # Python codeto demonstrate scope and lifetime of va riables #defining a function to print a number. def number( ): num = 50 print( "Value of num inside the function: ", num) num = 10 number() print( "Value of num outside the function:", num) Output: Value of num inside the function: 50 Value of num outside the function: 10
- 221. • Here, wecan see that the initial value of num is 10. Even though the function number() changed the value of num to 50, the value of num outside of the function remained unchanged. • This is because the capability's interior variable num is not quite the same as the outer variable (nearby to the capability). Despite having a similar variable name, they are separate factors with discrete extensions. • Factors past the capability are available inside the capability. The impact of these variables is global. We can retrieve their values within the function, but we cannot alter or change them. The value of a variable can be changed outside of the function if it is declared global with the keyword global.
- 222. Python sequences In whichorder you give input , in the same order you will receive output, so we call them as python sequences
- 223. Stringsin Python • Inpython, strings canbe created by enclosing the characteror the sequence ofcharacters in the quotes. • Python allows usto usesingle quotes, double quotes, or triple quotes to createstrings. Example: • In python, strings are treated as the sequence of characters which means that python doesn't support the character data type instead a single character written as 'p' is treated as the string of length1. str1 str2 = = 'Hello Python' "Hello Python" str3 = ' ' ' H e l l o Python'''
- 224.
- 225. StringIndexingin Python • Likeotherprogramming languages,the indexing of the pythonstrings starts from 0. Forexample,the string "HELLO"is indexed asgiven in the below figure. str="HELLO" s t r [ 0]=H s t r [ 1]=E s t r [ 4]=O • Python allows negative indexing for itssequences. • The index of -1 refers to the last item, -2 to the second last item and soon. str[-1]=O str[-2]=L str[-4]=E
- 226.
- 227. StringOperatorsin Python + Itis known asconcatenation operator used to join the strings. * It is known asrepetition operator. It concatenates the multiple copies of the samestring. [ ] It is known asslice operator. It is used to accessthe sub-strings of a particular string. [ :] It is known asrange slice operator. Itis usedto accessthe characters from the specifiedrange. in It is known asmembership operator. It returns if aparticular sub- string is present in the specifiedstring. not in Itis also amembership operator and does the exact reverse of in. It returns true if aparticular substring is not present in the specified string. r/R It is used to specify the raw string. Todefine any string asarawstring, the character r or Ris followed by the string. Suchas"hello n python". % It is used to perform string formatting. It makesuseof the format specifies usedin Cprogramming like %dor %fto map their valuesin python.
- 228. StringOperatorsin Python cont… Example:“stropdemo.py” str1 = "Hello" str2 = " World" print(str1*3) # prints HelloHelloHello print(str1+str2) # prints Hello world p r i n t ( s t r 1 [ 4 ] ) # prints o pr int ( s t r 1[ 2 : 4 ] ) # prints l l p r i n t ( ' w' i n str1) # prints false as w i s not present in str1 print('Wo' not i n str2) # prints false as W o i s present i n s t r 2 . pr int ( r 'Hello n world') # prints Hellon world as i t i s written print("The string str1 : %s"%(str1)) # prints The string s t r : Hello Output: pythonifdemo.py HelloHelloHello Hello World o ll False False Hellon world Thestring str1 : Hello
- 229.
- 230. StringFunctions& Methods inPython • Python provides various in-built functions & methods that are used for string handling. Thoseare • In python, len() function returns length of the given string. Syntax: len(string) • len() • lower() • upper() • replace() • join() • split() ☞ len(): • find() •index() • isalnum() • isdigit() • isnumeric() • islower() • isupper() Example: strlendemo.py str1="Python Language" p r i n t ( l e n ( s t r 1 ) ) Output: pythonstrlendemo.py 15
- 231. StringFunctions& Methods inPython Cont.. ☞ lower (): • In python, lower() method returns all characters of given string in lowercase. Syntax: str.lower() ☞ upper (): • In python, upper() method returns all characters of given string in uppercase. Syntax: str.upper() Example: strlowerdemo.py str1="PyTHOn" pr int (str1.lower()) Output: pythonstrlowerdemo.py python Example: strupperdemo.py str="PyTHOn" pr int (str.upper()) Output: python strupperdemo.py PYTHON
- 232. StringFunctions& Methods inPython Cont.. ☞ replace() • In python, replace() method replaces theold sequence of characters with the newsequence. Syntax: str.replace(old, new[, count]) Example: strreplacedemo.py s t r ="Java i s Obje c t- Orie n ted Java" str2= str.replace("Java","Python") print("Old String: n " , s t r ) print("New String: n " , s t r 2 ) str3 = str.replace("Java","Python",1) p r i n t ( " n Old String: n " , s t r ) print("New String: n " , s t r 3 ) Output: pythonstrreplacedemo.py Old String: Javais Object-Oriented and Java New String: Python is Object-Oriented andPython Old String: Javais Object-Oriented and Java New String: Python is Object-Oriented andJava
- 233. StringFunctions& Methods inPython Cont.. ☞ split(): • In python, split() method splits the string into acomma separated list. The string splits according to the spaceif the delimiter is not provided. Syntax: s tr.s plit ( [s ep= "delimiter " ]) Example: strsplitdemo.py str1 = "Python i s a programming language" str2 = s t r 1 . s p l i t ( ) p r i n t ( s t r 1 ) ; p r i n t ( s t r 2 ) str1 = "Python,is,a,programming,language" str2 = s t r 1 . s p l i t ( s e p = ' , ' ) p r i n t ( s t r 1 ) ; p r i n t ( s t r 2 ) Output: python strsplitdemo.py Java i s a programming language [ ' J a v a ' , ' i s ' , ' a ' , 'programming', 'language'] Java, i s , a, programming, language [ ' J a v a ' , ' i s ' , ' a ' , 'programming', 'language']
- 234. StringFunctions& Methods inPython Cont.. ☞ find(): • In python, find() method finds substring in the given string and returns index of the first match. It returns -1 if substring does not match. Syntax: s t r. f i n d ( s u b [ , s t a r t [ , e n d ] ] ) Example: strfinddemo.py str1 = "python i s a programming language" str2 = s t r 1 . f i n d ( " i s " ) str3 = s tr1. find ( "java" ) str4 = s t r 1 . f i n d ( " p " , 5 ) str5 = s t r 1 . f i n d ( " i " , 5 , 2 5 ) p r i n t ( s t r 2 ,s t r 3,str4 , s tr5) Output: pythonstrfinddemo.py 7 -1 12 7
- 235. StringFunctions& Methods inPython Cont.. ☞ index(): • In python, index() method is sameasthe find() method except it returns error on failure. Thismethod returns index of first occurred substring and an error if there is no matchfound. Syntax: Example: s t r . index(sub[, s t a r t [ , e n d ] ] ) strindexdemo.py s tr1 = "python is a programming language" str2 = s tr 1. index ("is" ) p r i n t ( s t r 2 ) str3 = str1.index("p",5) p r i n t ( s t r 3 ) str4 = str1.index("i",5,25) p r i n t ( s t r 4 ) s tr5 = s tr1. index( "java") p r i n t ( s t r 5 ) Output: pythonstrindexdemo.py 7 12 7 Substring not found
- 236. StringFunctions& Methods inPython Cont.. ☞ isalnum(): • In python, isalnum() method checkswhether the all characters ofthe string is alphanumeric or not. • Acharacter which is either aletter or anumber is knownas alphanumeric. It does not allow special chars evenspaces. Syntax: str.isalnum() Example: straldemo.py str1 = "python" str2 = "python123" str3 = "12345" str4 = "python@123" str5 = "python 123" p r i n t(s t r 1. is a lnum() ) p r i n t(s t r 2. is a lnum() ) p r i n t(s t r 3. is a lnum() ) p r i n t(s t r 4. is a lnum() ) p r i n t( s tr 5 . isa lnum()) Output: pythonstraldemo.py True True True False False
- 237. StringFunctions& Methods inPython Cont.. ☞ isdigit(): • In python, isdigit() method returns True if all the characters in the string are digits. It returns Falseif no character is digit in the string. Syntax: s t r. i s d i g i t ( ) Exampl e: strdigitdemo.py str1 = "12345" str2 = "python123" str3 = str4 = "123-45-78" " I I I V " Output: str5 = str6 = "/u00B23" # 23 "/u00BD" # 1/2 pythonstrdigitldemo.py True p r i n t ( s t r 1 . i s d i g i t ( ) ) print(str2.isdigit()) print(str3.isdigit()) print(str4.isdigit()) print(str5.isdigit()) print(str6.isdigit()) False Fals e Fals e True
- 238. StringFunctions& Methods inPython Cont.. ☞ isnumeric(): • In python, isnumeric() method checks whether all the characters of the string are numeric characters or not. It returns True if all the characters are numeric, otherwise returns False. Syntax: s t r . isnumeric() Example: strnumericdemo.py str1 = "12345" str2 = "python123" str3 = "123-45-78" str4 = " I I I V " str5 = "/u00B23" # 23 str6 = "/u00BD" # 1/2 print(str1.isnumeric()) print(str2.isnumeric()) print(str3.isnumeric()) print(str4.isnumeric()) print(str5.isnumeric()) print(str6.isnumeric()) Output: pythonstrnumericldemo.py True False False False True True
- 239. StringFunctions& Methods inPython Cont.. ☞ islower(): • In python, islower() method returns True if all characters in the string are in lowercase. It returns Falseif not in lowercase. Syntax: s tr.is low er ( ) Example: strlowerdemo.py str1 = "python" str2="PytHOn" str3="python3.7.3" p r in t( s tr 1.is low er ( ) ) p r in t( s tr 2.is low er ( ) ) p r in t( s tr 3.is low er ( ) ) Output: python strlowerldemo.py True False True
- 240. StringFunctions& Methods inPython Cont.. ☞ isupper(): • In python string isupper() method returns True if all characters in the string are in uppercase. It returns Falseif not in uppercase. Syntax: s t r.isupper( ) Example: strupperdemo.py str1 = "PYTHON" str2="PytHOn" str3="PYTHON 3 .7 .3" p r i n t( s tr1.isu pper()) p r i n t(s t r 2.isupper()) p r i n t(s t r 3.isupper()) Output: python strupperldemo.py True False True
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- 242.
- 243. Listin Python • Inpython, alist canbe defined asacollection of values or items. • Theitems in the list are separated with the comma (,) and enclosed with the square brackets []. Syntax: list-var =[ value1, value2, value3,….] Example: “listdemo.py” L1 = [ ] L2 = [123,"python", 3.7] L3 = [ 1 , 2, 3, 4, 5, 6] L4 = ["C","Java","Python"] p r i n t (L1) p r i n t (L2) p r i n t (L3) p r i n t (L4) Output: pythonlistdemo.py [ ] [123, 'python', 3.7] [ 1 , 2, 3, 4, 5, 6] [ ' C ' , ' J a v a ' , ' P y t h o n ' ]
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- 245. ListIndexingin Python • Likestring sequence, the indexing of the python lists starts from 0, i.e. the first element of the list is stored at the 0th index, the second element of the list is stored at the 1st index, and soon. • Theelements of the list canbe accessedby using theslice operator []. Example: mylist=[‘banana’,’apple’,’mango’,’tomato’,’berry’] • mylist[0]=”banana” • mylist[2]=”mango” mylist[1:3]=[”apple”,”mango”]
- 246. ListIndexingin Python cont… •Unlike other languages, python provides us the flexibility to use the negative indexing also. The negative indices are counted from the right. • The last element (right most) of the list has the index -1, its adjacent left element is present at the index -2 and so on until the left most elementis encountered. Example: mylist=[‘banana’,’apple’,’mango’,’tomato’,’berry’] • mylist[-1]=”berry” • mylist[-3]=”mango” mylist[-4:-2]=[“apple”,mango”]
- 247.
- 248. ListOperatorsin Python + It isknown asconcatenation operator used to concatenatetwo lists. * It is known asrepetition operator. It concatenates themultiple copies of the samelist. [] It is known asslice operator. It is usedto accessthe listitem from list. [:] It is known asrange slice operator. It is used to accesstherange of list items fromlist. in It is known asmembership operator. It returns ifaparticular item is present in the specifiedlist. not in It is also amembership operator and It returns true if a particular list item is not present in the list.
- 249. ListOperatorsin Python cont… Example:“listopdemo.py” num=[1,2,3,4,5] l a n g = [ ' p y t h o n ' , ' c ' , ' j a v a ' , ' p h p ' ] print(num + lang) #concatenates two l i s t s p r i n t (num * 2) #concatenates same l i s t 2 times print (lang[ 2]) # prints 2nd index value p r i n t ( lang[ 1: 4] ) #prints values from 1st to 3rd index. p r i n t ( ' c p p ' i n lang) # prints False print(6 not i n num) # prints True Output: python listopdemo.py [ 1 , 2, 3, 4, 5, 'python' , ' c ' , ' j a v a ' , ' p h p ' ] [ 1 , 2, 3, 4, 5, 1, 2, 3, 4, 5] java [ ' c ' , ' j a v a ' , ' php' ] False True
- 250. Howto updateor changeelementsto a list? • Python allows usto modify the list items by using the slice and assignment operator. • Wecan useassignment operator ( =) to change an item or a range of items. Example: “listopdemo1.py” num=[1,2,3,4,5] print(num) num[2]=30 print(num) num[1: 3] = [ 25, 36] print(num) num[4]="Python" print(num) Output: python listopdemo1.py [ 1 , 2, 3, 4, 5] [ 1 , 2, 30, 4, 5] [ 1 , 25, 36, 4, 5] [ 1 , 25, 36, 4, 'Python']
- 251. Howto delete orremoveelements from a list? • Python allows usto delete one or more items in alist by using the delkeyword. Example: “listopdemo2.py” num = [1,2,3,4,5] print(num) del num[1] print(num) del num[1: 3] print(num) Output: python listopdemo2.py [ 1 , 2, 3, 4, 5] [ 1 , 3, 4, 5] [ 1 , 5]
- 252. Iterating aList • Alist can be iterated by using a for - in loop. A simple list containing four strings can be iterated asfollows.. Example: “listopdemo3.py” lang=[ 'python' ,'c','java' , 'php ‘] print("The l i s t items are n " ) f o r i i n lang: p r i n t ( i ) Output: python listopdemo3.py The l i s t items are python c java php
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- 254. ListFunctions& Methods inPython • Python provides various in-built functions and methods which canbe used with list. Thoseare • len() • max() • min() • sum() • list() ☞ len(): • In Python, len() function is used to find the length of list,i.e it returns the number of items in the list.. Syntax: l e n ( l i s t ) Example: listlendemo.py num=[1,2,3,4,5,6] print("length of l i s t :",len(num)) Output: pythonlistlendemo.py length of list :6 • sorted() • append() • remove() • sort() • reverse() • count() • index() • insert() • pop() • clear()
- 255. ListFunctions& Methods inPython Cont.. ☞ max(): • In Python, max() function is used to find maximum value in the list. Syntax: max(list) Example: listmaxdemo.py list1=[ 1,2,3,4,5,6] l i s t 2 = [ ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ] print("Max of l i s t 1 : ", m ax( list 1) ) print("Max of l i s t 2 : ", m ax( list 2) ) Output: python listmaxdemo.py Max of list1 :6 Max of list2 :python
- 256. ListFunctions& Methods inPython Cont.. ☞ min(): • In Python, min() function is used to find minimum value in the list. Syntax: m i n ( l i s t ) Example: listmindemo.py list 1=[ 1,2,3,4,5,6] l i s t 2 = [ ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ] print("Min of l i s t 1 :",min(list1)) print("Min of l i s t 2 :",min(list2)) Output: pythonlistmindemo.py Min of list1 :1 Min of list2 :c
- 257. ListFunctions& Methods inPython Cont.. ☞ sum(): • In python, sum() function returns sum of all values in the list. List values must in numbertype. Syntax: sum(list) Example: listsumdemo.py list 1=[ 1,2,3,4,5,6] print("Sum of l i s t items : ", sum ( list 1) ) Output: python listsumdemo.py Sumof list items :21
- 258. ListFunctions& Methods inPython Cont.. ☞ list(): • In python, list() is used toconvert into list. given sequence (string or tuple) Syntax: list(sequence) Example: listdemo.py str="python" l i s t 1 = l i s t ( s t r ) p r i n t ( l i s t 1 ) Output: python listdemo.py ['p', 'y', 't', 'h', 'o','n']
- 259. ListFunctions& Methods inPython Cont.. ☞ sorted(): • In python, sorted() function is used to sort all items of list in an ascending order. Syntax: s o r t e d ( l i s t ) Example: sorteddemo.py num=[1,3,2,4,6,5] l a n g = [ ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ] print(sorted(num)) p r i n t ( sorted( la ng) ) Output: python sorteddemo.py [1, 2, 3, 4, 5,6] ['c', 'cpp', 'java','python']
- 260. ListFunctions& Methods inPython Cont.. ☞ append(): • In python, append() method adds an item to the end of the list. Syntax: list.append(item) where item may be number, string, list andetc. Example: appenddemo.py num=[1,2,3,4,5] lang=[ 'python' ,'java'] num.append(6) print(num) lang.append( " cpp" ) print(lang) Output: python appenddemo.py [1, 2, 3, 4, 5,6] ['python', 'java','cpp']
- 261. ListFunctions& Methods inPython Cont.. ☞ remove(): • In python, remove() method removes item from the list. It removes first occurrence of item if list contains duplicate items. It throws an error if the item is not present in the list. Syntax: list.remove(item) Example: removedemo.py list 1=[ 1,2,3,4,5] l i s t 2 = [ ' A ' , ' B ' , ' C ' , ' B ' , ' D ' ] list1.remove(2) p r i n t ( l i s t 1 ) l i s t 2 . remove( "B" ) p r i n t ( l i s t 2 ) list2.remove("E") p r i n t ( l i s t 2 ) Output: python removedemo.py [1, 3, 4,5] ['A', 'C', 'B','D'] ValueError: xnot in list
- 262. ListFunctions& Methods inPython Cont.. ☞ sort(): • In python, sort() method sorts the list elements into descending or ascending order. Bydefault, list sorts the elements into ascending order. It takes an optional parameter 'reverse' which sorts the list into descendingorder. Syntax: list . sor t( [reverse=tr ue]) Example: sortdemo.py list1=[6,8,2,4,10] l i s t 1 . s o r t ( ) p r i n t ( " n After Sorting: n") p r i n t ( l i s t 1 ) p r i n t ( "Descend ing Order: n") list1.sort(reverse=True) p r i n t ( l i s t 1 ) Output: pythonsortdemo.py After Sorting: [2, 4, 6, 8 ,10] Descending Order: [10, 8, 6, 4 ,2]
- 263. ListFunctions& Methods inPython Cont.. ☞ reverse(): • In python, reverse() method reverses elements of the list. i.e. the last index value of the list will be present at 0th index. Syntax: l i s t . r e v e r s e ( ) Example: reversedemo.py list1=[6,8,2,4,10] list1. reverse() p r i n t ( " n After reverse: n") p r i n t ( l i s t 1 ) Output: python reversedemo.py After reverse: [10, 4, 2, 8 ,6]
- 264. ListFunctions& Methods inPython Cont.. ☞ count(): • In python, count() method returns the number of times an element appears in the list. If the element is not present in the list, it returns 0. Syntax: list.count( item) Example: countdemo.py num=[1,2,3,4,3,2,2,1,4,5,8] cnt=num.count(2) print("Count of 2 i s : " , c n t ) cnt=num.count(10) p r i n t ( "Count of 10 i s : " , cnt) Output: pythoncountdemo.py Count of 2 is:3 Count of 10 is:0
- 265. ListFunctions& Methods inPython Cont.. ☞ index(): • In python, index () method returns index of the passedelement.If the element is not present, itraises aValueError. • If list contains duplicate elements, it returns index of first occurred element. • Thismethod takes two more optional parameters start and end which are used to search index withinalimit. Syntax: l i s t . index(item [ , s t a r t [ , end]]) Example: indexdemo.py l i s t 1 = [ ' p ' , ' y ' , ' t ' , ' o ' , ' n ' , ' p ' ] p r i n t ( l i s t 1 . i n d e x ( ' t ' ) ) P r i n t ( l i s t 1 . i n d e x ( ' p ' ) ) P r i n t ( l i s t 1 . i n d e x ( ' p ' , 3 , 1 0 ) ) P r i n t ( l i s t 1 . i n d e x ( ' z ' ) ) ) Output: python indexdemo.py 2 0 5 Value Error
- 266. ListFunctions& Methods inPython Cont.. ☞ insert(): • In python, insert() method inserts the element at the specified index in the list. The first argument is the index of the element before which to insert theelement. Syntax: list . ins er t ( i n de x, it em ) Example: insertdemo.py num=[10, 20, 30, 40, 50] num.insert( 4, 60) print(num) num.insert( 7, 70) print(num) Output: pythoninsertdemo.py [10, 20, 30, 40, 60,50] [10, 20, 30, 40, 60, 50,70]
- 267. ListFunctions& Methods inPython Cont.. ☞ pop(): • In python, pop() element removes an element present at specified index from thelist. Syntax: list.pop(index) Example: popdemo.py num=[10,20,30,40,50] num.pop() p r i n t (num) num.pop( 2) p r i n t (num) num.pop( 7) p r i n t (num) Output: pythonpopdemo.py [10, 20, 30,40] [10, 20, 40] IndexError: Out of range
- 268. ListFunctions& Methods inPython Cont.. ☞ clear(): • In python, clear() method removes all the elements from the list. It clears the list completely and returns nothing. Syntax: l i s t . c l e a r ( ) Example: cleardemo.py num=[10,20,30,40,50] num.clear( ) print(num) Output: python cleardemo.py [ ]
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- 270.
- 271. Tuplein Python • Inpython, atuple is asequence of immutable elements oritems. • Tuple is similar to list since the items stored in the list can be changed whereas the tuple is immutable and the items stored in the tuple cannot bechanged. • A tuple can be written as the collection of comma-separated values enclosed with the small brackets (). Syntax:var =( value1, value2, value3,….) Example: “tupledemo.py” t1 = ( ) t2 = ( 123, "python", 3. 7) t3 = ( 1 , 2, 3, 4, 5, 6) t4 = ( "C " ,) p r i n t( t 1 ) p r i n t( t 2 ) p r i n t( t 3 ) p r i n t( t 4 ) Output: python tupledemo.py ( ) (123, 'python', 3.7) ( 1 , 2, 3, 4, 5, 6) ( ' C ' , )
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- 273. TupleIndexingin Python • Likelist sequence, the indexing of the python tuple starts from 0, i.e. the first element of the tuple is stored at the 0th index, the second element of the tuple is stored at the 1st index, and soon. • Theelements of the tuple canbe accessedby using theslice operator []. Example: mytuple=(‘banana’,’apple’,’mango’,’tomato’,’berry’) • mytuple[0]=”banana” • mytuple[2]=”mango” mytuple[1:3]=[”apple”,”mango”]
- 274. TupleIndexingin Python cont… •Unlike other languages, python provides us the flexibility to use the negative indexing also. The negative indices are counted from the right. • The last element (right most) of the tuple has the index -1, its adjacent left element is present at the index -2 and so on until the left most elementis encountered. Example: mytuple=*‘banana’,’apple’,’mango’,’tomato’,’berry’+ • mytuple[-1]=”berry” • mytuple[-3]=”mango” mytuple[-4:-2]=[“apple”,mango”]
- 275.
- 276. TupleOperatorsin Python + It isknown asconcatenation operator used to concatenatetwo tuples. * It is known asrepetition operator. It concatenates themultiple copies of the sametuple. [] It is known asslice operator. It is usedto accessthe itemfrom tuple. [:] It is known asrange slice operator. It is used to accesstherange of items from tuple. in It is known asmembership operator. It returns ifaparticular item is present in the specifiedtuple. not in It is also amembership operator and It returns true if a particular item is not present in the tuple.
- 277. TupleOperatorsin Python cont… Example:“tupleopdemo.py” num=(1,2,3,4,5) l a n g = ( ' p y t h o n ' , ' c ' , ' j a v a ' , ' p h p ' ) print(num + lang) #concatenates two tuples p r i n t (num * 2) #concatenates same tuple 2 times print (lang[ 2]) # prints 2nd index value p r i n t ( lang[ 1: 4] ) #prints values from 1st to 3rd index. p r i n t ( ' c p p ' i n lang) # prints False print(6 not i n num) # prints True Output: python tupleopdemo.py ( 1 , 2, 3, 4, 5, 'python' , ' c ' , ' j a v a ' , ' p h p ' ) ( 1 , 2, 3, 4, 5, 1, 2, 3, 4, 5) java ( ' c ' , ' j a v a ' , ' php' ) False True
- 278. Howto addor removeelementsfrom a tuple? • Unlike lists, the tuple items cannot be updated or deleted as tuples areimmutable. • Todelete an entire tuple, we can usethe del keyword with the tuple name. Example: “tupledemo1.py” t u p = ( ' p y t h o n ' , ' c ' , ' j a v a ' , ' p h p ' ) tup[3]="html" p r i n t ( tup) del tup[3] p r i n t ( tup) del tup Output: python tupledemo1.py 'tuple' object does not support item assignment 'tuple' object doesn't support item deletion
- 279. Iterating atuple • Atuplecan be iterated by using afor - in loop. Asimple tuple containing four strings can be iterated asfollows.. Example: “tupledemo2.py” l a n g = ( ' p y t h o n ' , ' c ' , ' j a v a ' , ' p h p ' ) print("The tuple items are n " ) f o r i i n lang: p r i n t ( i ) Output: python tupledemo2.py The tuple items are python c java php
- 280.
- 281. TuplesFunctions& Methods inPython • Python provides various in-built functions and methods which canbe used with tuples. Thoseare • len() • max() • min() • sum() ☞ len(): • In Python, len() function is used to find the length of tuple,i.e it returns the number of items in the tuple. Syntax: len(tuple) Example: lendemo.py num=(1,2,3,4,5,6) print("length of tuple :",len(num)) Output: pythonlendemo.py length of tuple :6 • tuple() •sorted() • count() • index()
- 282. TupleFunctions& Methods inPython Cont.. ☞ max(): • In Python, max() function is used to find maximum value in the tuple. Syntax: max(tuple) Example: maxdemo.py t1=(1,2,3,4,5,6) t 2 = ( ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ) print("Max of Tuple t1 :",max(t1)) print("Max of Tuple t2 :",max(t2)) Output: python maxdemo.py Max of Tuple t1 :6 Max of Tuple t2 :python
- 283. TupleFunctions& Methods inPython Cont.. ☞ min(): • In Python, min() is used to find minimum value in the tuple. Syntax: min(tuple) Example: mindemo.py t1=(1,2,3,4,5,6) t 2 = ( ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ) print("Min of Tuple t1 :",min(t1)) print("Min of Tuple t2 :",min(t2)) Output: pythonmindemo.py Min of Tuple t1 : 1 Min of Tuple t2 : c
- 284. TupleFunctions& Methods inPython Cont.. ☞ sum(): • In python, sum() function returns sum of all values in the tuple. The tuple values must in numbertype. Syntax: sum(tuple) Example: sumdemo.py t1=(1,2,3,4,5,6) print("Sum of tuple items :",sum(t1)) Output: python sumdemo.py Sumof tuple items :21
- 285. TupleFunctions& Methods inPython Cont.. ☞ tuple(): • In python, tuple() is used toconvert into tuple. given sequence (string or list) Syntax: tuple(sequence) Example: tupledemo.py str="python" t1=tuple(str) p r i n t ( t 1 ) num=[1,2,3,4,5,6] t2=tuple(num) p r i n t ( t 2 ) Output: pythontupledemo.py ('p', 'y', 't', 'h', 'o','n‘) (1, 2, 3, 4, 5,6)
- 286. TupleFunctions& Methods inPython Cont.. ☞ sorted(): • In python, sorted() function is used to sort all items of tuple in an ascending order. Syntax: sorted(tuple) Example: sorteddemo.py num=(1,3,2,4,6,5) l a n g = ( ' j a v a ' , ' c ' , ' p y t h o n ' , ' c p p ' ) print(sorted(num)) p r i n t ( sorted( la ng) ) Output: python sorteddemo.py (1, 2, 3, 4, 5,6) ('c', 'cpp', 'java', 'python')
- 287. TupleFunctions& Methods inPython Cont.. ☞ count(): • In python, count() method returns the number of times an element appears in the tuple. If the element is not present in the tuple, it returns 0. Syntax: tuple.count(item) Example: countdemo.py num=(1,2,3,4,3,2,2,1,4,5,8) cnt=num.count(2) print("Count of 2 i s : " , c n t ) cnt=num.count(10) p r i n t ( "Count of 10 i s : " , cnt) Output: pythoncountdemo.py Count of 2 is:3 Count of 10 is:0
- 288. TupleFunctions& Methods inPython Cont.. ☞ index(): • In python, index () method returns index of the passedelement.If the element is not present, itraises aValueError. • If tuple contains duplicate elements, it returns index of first occurred element. • Thismethod takes two more optional parameters start and end which are used to search index withinalimit. Syntax: tuple.index(item [ , s t a r t [ , end]]) Example: indexdemo.py t 1 = ( ' p ' , ' y ' , ' t ' , ' o ' , ' n ' , ' p ' ) p r i n t ( t 1 . i n d e x ( ' t ' ) ) P r i n t ( t 1 . i n d e x ( ' p ' ) ) Pr int ( t1.index( 'p' , 3,10)) P r i n t ( t 1 . i n d e x ( ' z ' ) ) ) Output: python indexdemo.py 2 0 5 Value Error
- 290. Python dictionary isan unordered collection of items. While other compound data types have only value as an element, a dictionary has a key: value pair. Dictionaries are optimized to retrieve values when the key is known.
- 291. Creating a dictionaryis as simple as placing items inside curly braces {} separated by comma. Each element in a dictionary is represented by a key:value pair. While values can be of any data type and can repeat, keys must be of immutable type and must be unique. mohammed.sikander@cranessoftware.com 3
- 292. While indexing isused with other container types to access values, dictionary uses keys. Key can be used either inside square brackets or with the get() method. The difference while using get() is that it returns None instead of KeyError, if the key is not found.
- 293. Dictionary are mutable.We can add new items or change the value of existing items using assignment operator. If the key is already present, value gets updated, else a new key: value pair is added to the dictionary.
- 294. We can removea particular item in a dictionary by using the method pop(). This method removes as item with the provided key and returns the value. All the items can be removed at once using the clear() method. We can also use the del keyword to remove individual items or the entire dictionary itself.
- 296. The method, popitem()can be used to remove and return an arbitrary item (key, value) form the dictionary. RaisesKeyErrorif the dictionary is empty.
- 298. Wecantest if akeyis in adictionary or not using the keywordin. Notice that membership test is for keysonly, not for values.
- 299. Using afor loopwe caniterate through each key in adictionary.
- 302. Method Description clear() Removeallitems form the dictionary. copy() Returnashallowcopy of the dictionary. fromkeys(seq[, v]) Return anewdictionary with keysfrom seq andvalueequalto v(defaults to None). get(key[,d]) Return the value of key. If key doesnotexit, return d (defaults to None). items() Return anewview of the dictionary'sitems (key, value). keys() Returnanewview of the dictionary'skeys. pop(key[,d]) Removethe item with key andreturn its value or d if key isnot found. If d is not provided andkey isnot found, raisesKeyError. popitem() Removeandreturn anarbitaryitem (key, value). Raises KeyError if the dictionary is empty. setdefault(key[,d]) If key is in the dictionary,return its value. If not, insert key with avalueof d and return d (defaults to None). update([other]) Updatethe dictionary with the key/value pairs from other, overwritingexisting keys. values() Returnanewview of the dictionary'svalues
- 303. Function Description len() Returnthelength (the number of items) in the dictionary. sorted() Returnanew sorted list of keys in the dictionary.
- 305. # Definition ofcountry and capital countries =['spain', 'france', 'germany', 'norway','india'] capitals =['madrid','paris', 'berlin', 'oslo','delhi'] I would like to print the capital of germany. # Get index of 'germany': ind_ger # Useind_ger to print out capital of Germany
- 307. If you knowhow to accessadictionary, you can also assignanew value to it. Toadd anew key-valuepair to countryCapitals, you canusesomething like this: countryCapitals[‘india’] =‘delhi’
- 308. To remove aentry from dictionary, we can use del method. Remove norway del (countryCapitals[‘norway’])
- 310. Create aDictionary whichrecords the major cities ofeach state. {state : [major cities] }
- 311. Dictionaries cancontain key:valuepairs where the valuesareagain dictionaries.
- 314. Aset is anunorderedcollection of items. Everyelement is unique and mustbe immutable. However, the set itself is mutable.Wecanadd or remove items fromit. Setscanbe usedto perform mathematical set operations like union, intersection, symmetric difference etc.
- 315. A set iscreated by placing all the elements inside curly braces{}, separated by comma or by using the built-in function set(). The elements can be of different types (integer, float, tuple, string etc.). But a set cannot have a mutable element, like list, set or dictionary, as its element.
- 316. A set cancontain elements of different type A set cannot contain lists. We can convert a list to set using set function
- 317.
- 318. Setsare mutable. Butsincethey areunordered, indexing haveno meaning. Wecannotaccessor changeanelement of set usingindexing or slicing. Wecanadd singleelement using the add()method and multiple elements using the update() method. Theupdate() method cantake tuples, lists, strings or other sets asits argument. In all cases,duplicates are avoided.
- 319. A particular itemcan be removed from setusing methods, discard() and remove(). using discard() if the item does not exist in the set, it remains unchanged. But remove() will raise an error in such condition.
- 320. We can testif an item exists in a set or not, using the in operator.
- 321. Givenanlist of elements,removethe duplicateelement.
- 322. Read a stringand find the number of unique characters in it.
- 323. Sets can beused to carry out mathematical set operations like union, intersection, difference and symmetric difference. Wecando this with operators or methods. Method Operator union | intersection & difference - symmetric_difference ^
- 328. Wehaveseenthe applicationsof union,intersection, differenceandsymmetricdifferenceoperations,but these operationsdo not makeany changesor mutations to the set. Wecan use the following operations to createmutations to a set: Method Operator update |= Update the set by adding elements from an iterable/anotherset. intersection_update &= Update the set by keeping only the elements found in it and an iterable/another set. Difference_update -= Update the set by removing elements found in an iterable/another set. symmetric_difference_update ^= Update the set by only keeping the elements found in either set, but not in both.
- 329. Isdisjoint–This method willreturnTrueif two set have anullintersection Issubset–This method reports whether another set contains this set Issuperset–Thismethod will report whether this set contains another set