PART - 1 Python Introduction- Variables- Data types - Numeric- String- Boolean.pptx.pdf

ASHA NIVEDITHA
SOFTWARE TECHNICAL TRAINER

PROGRAMMING
LANGUAGE
•A programming language is a type of
written language that tells computers
what to do.
•A "program" in general, is a sequence
of instructions written so that a
computer can perform certain task.

Types of programming languages
The programming languages are broadly classified into three types,
• Low-level language
• High-level language
• Middle-level language

Low-level langu
age
It is machine-dependent.
It works based on the binary number
0’s and 1’s.
The processor runs low-level programs
directly without the need of a compiler
or interpreter so the program written in
low-level language can be run very fast.

High-level programming language
High-level programming language (HLL) is designed for developing
user-friendly software programs and websites.
This programming language requires a compiler or interpreter to
translate the program into machine language (execute the program).
Example: Python, Java, JavaScript, PHP, C#, C++, etc.

Middle-level programming language
Middle-level programming language lies between the low-level programming language and the
high-level programming language.
It is also known as the intermediate programming language and pseudo-language.
A middle-level programming language's advantages are that it supports the features of
high-level programming, it is a user-friendly language, and is closely related to machine
language and human language.
Example: C, C++, language

PYTHON
Interpreted programming language
Dynamic
Object Oriented
Versatile scripting language
Multiple programming paradigms.

PROGRAMMING
VS
SCRIPTING
Scripts are few lines of code used
within a program. These scripts
are written to automate some
particular tasks within the
program.
Programming languages are a set
of code/instructions for the
computer that are compiled at
runtime. Thus an exe file is
created

Advantages and Disadvantages of Python

HISTORY
Python was created by Guido van Rossum,
and first released on February 20, 1991.
While you may know the python as a large
snake, the name of the Python
programming language comes from an old
BBC television comedy sketch series called
Monty Python's Flying Circus.

FEATURES
Easy to read and learn
Free and Open source
Cross platform
Large standard library
Extensible
GUI Programming support

APPLICATIONS
Web applications
GUI based desktop
applications(Games,
Scientific
Applications)
Operating Systems
Enterprise and
Business
applications
Audio or video
based applications
3D CAD application

DOWNLOADING AND INSTALLATION
Visit the link https://www.python.org

Ways to run Python Scripts
1. Command Line [python script.py]
✔ Open a terminal or command prompt.
✔ Navigate to the directory containing your Python script using the cd command.
2. IDLE (Python's Integrated Development and Learning Environment):
✔ Open IDLE and use the "File" menu to open your script, then run it.
3. Jupyter Notebooks [Using interpreter interactively]
✔ If you are using Jupyter Notebooks, you can run individual cells or the entire notebook.
✔ Use the "Run" button or press Shift + Enter to execute a cell.

IDE
An integrated development
environment (IDE) is a
software application that
helps programmers develop
software code efficiently. It
increases developer
productivity by combining
capabilities such as software
editing, building, testing, and
packaging in an easy-to-use
application.

ANACONDA PYTHON
Anaconda is a distribution of the Python
and R programming languages for
scientific computing (data science,
machine learning applications,
large-scale data processing, predictive
analytics, etc.), that aims to simplify
package management and
deployment.

VARIABLE
• In Python, variables are a storage placeholder for texts and numbers.
• It must have a name so that you are able to find it again
• The variable is always assigned with the equal sign, followed by the value of the variable.
• A variable is created the moment we first assign a value to it.
Example:
a=10
b=“IBM”
print(a)
Print(b)

RULES FOR CREATING VARIABLES
Must start with a letter or the underscore character
Cannot start with a number
Can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
Case-sensitive (name, Name and NAME are three different variables)
The reserved words(keywords) cannot be used naming the variable

Assigning a
single value
to multiple
variables
Example::
x=y=z= 100
print(x)
print(y)
print(z)

Assigning
different values
to multiple
variables
Example:
x, y, z =10, 20.20, “IBM CE”
print(x)
print(y)
print(z)

Can we use
same name
for different
types?
If we use same name, the variable
starts referring to new value and type.
Example:
x=23
x=“salary”
print(x)

How does +
operator work
with variables
Example:
x = 100
y = 200
print(x + y)
x = "IBM"
y = "CE"
print(x + y)

Can we use + for different
types also?
‘+’ used for adding different data types will produce an error.
Example:
age= 10
name = "David"
print(age+name)
OUTPUT: TypeError: unsupported operand type(s) for +: 'int'
and 'str'

Keywords
•Keywords are special reserved words
which convey a special meaning to the
compiler/interpreter.
•Each keyword have a special meaning
and a specific operation.
import keyword
print(keyword.kwlist)

IO OPERATIONS
•print( ) - Used for output operation
•input( ) - Used for input operations.
name = input()
number = int(input())
print ('my name is:’, name, 'and my age is:',
number)

DATA TYPES
Immutable Data Types
Numeric types(int, float, complex)
Tuple
String and Boolean
Mutable Data Types
List
Dictionary
Set

Data Types:-
Variables will hold values, and every value has its own
data-type.
Python is a dynamically typed language
Hence we do not need to define the type of the variable
while declaring it.
The interpreter implicitly binds the value with its type.

a = 5
The variable a holds integer value five and we did not define
its type. Python interpreter will automatically interpret
variables a as an integer type.
Python enables us to check the type of the variable used in the
program. Python provides us the type() function, which
returns the type of the variable passed.

Numeric Datatype :-
Numeric values are known as numbers.
There are three types.
integer, float, and complex
(They may be +ve /-ve)
Python provides the type() function to know the data-type
of the variable.

Example: Output:
x=1 #integer <Class ‘int’>
y=13.6 #float <Class ‘float’>
z=6+1j #complex <Class ‘complex’>
print(type(x))
print(type(y))
print(type(z))

Comments
Helps explaining Python code.
make the code more readable.
prevent execution when testing code.
Comments starts with a #, and Python will ignore them

Constants
A constant is a special type of variable whose value cannot
be changed.
import constant
print(constant.PI) # prints 3.14
print(constant.GRAVITY) # prints 9.8

Type Conversion:-
#convert from int to float:
x = 1
a = float(x)
print(a)
#convert from float to int:
y = 2.8
b = int(y)
print(b)
#convert from int to complex:
z = 1
c = complex(z)
print(c)

Points to Remember:-
All the keywords must be used as they have defined.
(Uppercase and Lower Case)
Keywords should not be used as identifiers like variable names,
functions name, class name, etc.
The meaning of each keyword is fixed, we can not modify or
remove it.

Booleans
Booleans represent one of two values: True or False.
Input: Output:
print(10 > 9) True
print(10 == 9) False

Strings
String is a sequence of characters.
String may contain alphabets, numbers and special characters.
Usually strings are enclosed within a single quotes and double
quotes.
Example: a= “hello world‟ b= ‘Python’
We can display a string literal with the
print() function.

Example 1:
String1 ="I'm a technical lead"
print(String1)
Example 2 :
String2 ='I'm a technical lead’
print(String2)
Example 3:
String3 ='''I'm a technical lead and “tester”"'
print(String3)
Example 4:
String4 =‘‘‘python
for
datascience ”’
print(String4)

OUTPUT for Example 1:
I'm a technical lead
SyntaxError: invalid syntax
I'm a technical lead and "tester"
python
for
datascience

Multiline Strings
We can assign a multiline string to a variable by using three quotes.
a = ""“You get
What you work for
Not what you
wish for."""
print(a)

Strings in Python are arrays of bytes representing unicode characters.
Python does not have a character data type, a single character is simply a
string with a length of 1.
Square brackets can be used to access elements of the string.
Indexing:-
a = "Hello, World!"
print(a[1])

Accessing characters in Python
Individual characters of a String can be accessed by using
the method of Indexing.
To access a range of characters in the String, method of
slicing is used.( done by using a Slicing operator (colon)).

Strings indexing and splitting
The indexing of the python strings starts from 0.

b = "Hello, World!"
print(b[3:-5])
Slicing:-
b = "Hello,World!"
print(b[2:5])
b = "Hello,World!"
print(b[:5])
b = "Hello,World!"
print(b[2:])

Output:
b="hello,world!"
print(b)
print(b[2:5])
print(b[2:])
print(b[:5])
print(b[3:-5])
hello,world!
llo
llo,world!
hello
lo,w

Deleting/Updating from a String
Updation or deletion of characters from a String is not allowed.
This will cause an error because item assignment or item
deletion from a String is not supported.
Although deletion of entire String is possible with the use of a
built-in del keyword.
This is because Strings are immutable, hence elements of a
String cannot be changed once it has been assigned.
Only new strings can be reassigned to the same name.

Deleting Entire String:(using del keyword)
Example:
String1 = "Hello, I'm john"
print(String1)
# Deleting entire String
del String1
print("nDeleting the entire string ")
print(String1)

OUTPUT:
Hello, I'm john
Deleting the entire string
NameError: name 'String1' is not defined

Find the output
str1="IBM"
print(str1[5])
print(str1)
OUTPUT:
IndexError: string index out of range
IBM

NOTE
✔ While accessing an index out of the range will cause an Index
Error.
✔ Only Integers are allowed to be passed as an index, float or
other types will cause a TypeError.

String operations
Concatenation of Two or More Strings
Removes any whitespace from the beginning or the end
The length of a string
Strings in lower case
Strings in upper case
Replaces a string with another string
Splits the string into substrings

Concatenation of Two or More Strings
Joining of two or more strings into a single one is called
concatenation.
Example:
str1 = "python"
str2 ="programming"
# using +
print("str1 + str2 = ", str1 + str2)
OUTPUT:
str1 + str2 = pythonprogramming

Example:
str1 = "python"
# using *
print('str1 * 3 =', str1 * 3)
OUTPUT:
str1 * 3 = pythonpythonpython

Removes any whitespace from the beginning or the
end
Example:
A = “ Hello, World! ”
print(A)
a = " Hello, World! “
print(a.strip())
OUTPUT:
Hello, World!
Hello, World!

To find the the length of a string
Example:
a = "Hello, World!"
print(len(a))
OUTPUT:
13

Strings in lower case
Example:
a = "HELLO, World!"
print(a.lower())
OUTPUT:
hello, world!

Strings in upper case
Example:
a = "Hello, World!"
print(a.upper())
OUTPUT:
HELLO, WORLD!

Replaces a string with another string
Example:
a = "Hello, World!"
print(a.replace("H", “F"))
OUTPUT:
Fello, World!

Splits the string into substrings
Example:
a = "Hello, World!"
print(a.split(","))
OUTPUT:
['Hello', ' World!']

PART - 1 Python Introduction- Variables- Data types - Numeric- String- Boolean.pptx.pdf

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