The document provides an introduction and comparison of Python and C programming languages. Some key points: - Python is an interpreted language while C needs compilation. Python makes program development faster. - Variables, input/output, arrays, control structures like if/else, for loops work differently in Python compared to C. - Python uses lists instead of arrays. Lists are mutable and support slicing. - Strings are treated as character lists in Python. - Functions are defined using def keyword in Python. - The document also introduces sequences (strings, tuples, lists), dictionaries, and sets in Python - their usage and operations.

1. Introduction To Python
Basics, sequences, Dictionaries, Sets

2. Python
– Python is an interepted language, which can save you considerable time
during program development because no compilation and linking is
necessary.

3. How to install Python
• Download latest version of python and install it on any drive: say
D:python
• Then follow the steps
–Got to Control Panel -> System -> Advanced system settings
–Click the Environment variables... button
–Edit PATH and append ;d:Python to the end
–Click OK.
–Open command prompt type python and enter

4. C Vs Python
Syntax comparison

5. Commenting
// comment single line
/* comment
multiple lines */
# comment single line
“ ” ” comment
multiple lines “ ” ”
C Python

6. Variables
//Declaring a variable
Int a=10;
Char c=‘a’;
Float f=1.12;
//Cannot assign multiple values
a=b=4 // Will result error
#No need of prior Declarations
a=10
c=‘a’
f=1.12
#Can assign multiple values simultaneously
x = y = z = 10
a, b, c = 1, 2, "john"
C Python

7. OutPut
printf(“Hello baabtra”);
Int a=10,b=25;
Printf(“%d %d”,a,b);
Printf(“value of a=%d and b= %d”,a,b)
print(“Hello baabtra”)
a=10
b=25
print(a,b)
print (“value of a=%d and b= %d” % (a,b))
C Python

8. InPut
int a;
Printf(“Enter the number”);
scanf(“%d”,&a);
a=input(“Enter the number”)
C Python

9. Arrays
int a[]={12,14,15,65,34};
printf(“%d”, a[3]);
No Arrays ! Instead Lists
a = [12,14,15,16,65,34,’baabtra’]
C Python

10. Arrays
int a[]={12,14,15,65,34};
printf(“%d”, a[3]);
No Arrays ! Instead Lists
a = [12,14,15,16,65,34,’baabtra’]
C Python
[ 12 , 14 , 15 , 16 , 65 , 34 , ’baabtra’ ]
0 1 2 3 4 5 6
-7 -6 -5 -4 -3 -2 -1

11. Lists in detail
• Print(a[2:5]) # prints 15,16,65
• Print(a[-6:-2]) # prints 14,15,16,65
• Print(a[4:]) # prints 65,34,baabtra
• Print(a[:2]) # prints 12,14,15
• a[2] = a[2] + 23; # Lists are mutable,we can change individual items
• a[0:2] = [1, 12] # We can replace a group of items together
• a[0:2] = [] # We can remove items together
• a[:] = [] # Clear the list

12. Lists in detail
• a.append(25) # adds an element at the end of list
• b =[55,66,77]
a.extend(b)
a=a+b;
• a.insert(1,99) # Inserts 99 at position 1
• a.pop(0) # pop elements at position 0
# Combines two lists

13. Strings
char a[]=“baabtra”; a= ‘baabtra’
b=“doesn’t”
C=“baabtra ”mentoring partner””
Strings are character lists, So can be used like any
other lists as we discussed earlier
print (a[0])
a.append(“m”);
C Python

14. Strings in detail
• String slicing
word=‘hello baabtra’
print(word[6:] # prints baabtra
word[: 6] # prints ‘hello ‘
word2= ‘good morning’ + word[6:]
Print(word2) # prints ‘good morning baabtra‘

15. Control structures
• Conditional Control Structures
• If
• If else
• Switch
• Loops
• For
• While
• Do while
Conditional Control Structures
• If
• If else
• Switch
Loops
• For
• While
•Do while
C Python

16. If else
int a;
Printf(“Enter the number”);
scanf(“%d”,&a);
If(a>80)
Printf(“Distiction”);
else if(a>60)
Printf(“First class”);
else {
Printf(“Poor performancen”);
Printf(“Repeat the examn”); }
a=input(“Enter the number”)
if a>80 : print(“Distinction”)
elif a>60 : print(“First Class”)
else :
print(“Poor performance”)
print(“Repeat the exam”)
C Python

17. While Loop
int i=0;
whil(i<10)
{
printf(“%d”, i);
i=i+1;
}
i=0
while i<10:
print(i)
i=i+1
C Python

18. For Loop
int i=0;
for(i=0;i<10;i++)
{
printf(“%d”, i);
}
It’s quite a bit untraditional . We need to
define a range on which loop has to iterate.
This can be done using
Range(10,20) // creating a list with
elements from 10 to 20
For i in range(10) :
print(i) //print numbers up to 10
a=[12,14,16,’baabtra’]
For i in a :
print(i) //prints 12,14,16,baabtra
C Python

19. Other Control structure statements
• Break
Eg: If(a%2==0)
{
Print(“even”);
break;
}
• Break
The break statement is allowed only inside a loop
body. When break executes, the loop terminates.
Eg: for x in range(2, n):
if n % x == 0:
print n, 'equals', x, '*', n/x
break
C Python

20. Other Control structure statements
• Continue
for(i=1;i<20;i++)
{
if(i%2==1)
Continue;
Print(“%d is even”,i);
}
• Continue
The continue statement is allowed only inside a
loop body. When continue executes, the current
iteration of the loop body terminates, and
execution continues with the next iteration of the
loop
Eg:
For i in range(1,20)
If i%2==0:
continue
print(“%d is even” %(i))
C Python

21. Other Control structure statements
for(i=1;i<20;i++)
{
if(i%2==1)
{}
else
Print(“%d is even”,i);
}
• pass
The pass statement, which performs no action,
can be used when you have nothing specific to do.
Eg:
if a<10:
print(“less than 10”)
elif x>20:
pass # nothing to be done in this case
Else:
print(“in between 10 and 20”)
C Python

22. Functions
Int findSum(int a,int b)
{
int c;
c=a+b;
return c
}
d=findSum(10,15);
def findSum(a,b) :
return a+b
sum=findSum(112,321)
print(sum)
C Python

23. Task
• Write a simple python program which will have an array variable as below
• a= [50,15,12,4,2]
• Create 3 functions which will take the above array as argument and returns
the arithmetic output
–Add() //Outputs 83
–Substract() //Outputs 17
–Multiply() //Outputs 72000

24. That was the comparison !
So what’s new in python?

25. Sequences

26. Sequences
• A sequence is an ordered container of items, indexed by non-
negative integers. Python provides built-in sequence types ,they
are:-
– Strings (plain and Unicode), // We already have discussed
– Tuples
– Lists // We already have discussed

27. Tuples

28. Tuples
• A tuple is an immutable ordered sequence of items which may be of different
types.
– (100,200,300) # Tuple with three items
– (3.14,) # Tuple with one item
– ( ) # Empty tuple
• Immutable means we cant change the values of a tuple
• A tuple with exactly two items is also often called a pair.

29. Operation on Tuples
tpl_laptop = ('acer','lenova','hp','TOSHIBA')
tpl_numbers = (10,250,10,21,10)
tpl_numbers.count(10) # prints 3
tpl_laptop.index('hp') # prints 2

30. Task
• Create a python program that will accept two tuples as arguments
and return the difference between the tuple values,

31. Dictionaries

32. Dictionaries
• A dictionary is an arbitrary collection of objects indexed by nearly
arbitrary values called keys. They are mutable and, unlike
sequences, are unordered.
–Eg :{ 'x':42, 'y':3.14, 'z':7 }
–dict([[1,2],[3,4]]) # similar to {1:2,3:4}

33. Operation on Dictionaries
• dic={'a':1,'b':2,'c':3}
– len(dic) # returns 3
– del dic['a'] # removes element with key ‘a’
– a in dic # returns ‘True’ .Bur
– dic.items() #Displays elements
– for i in dic.iterkeys():
... print i # Returns key
– for i in dic. itervalues():
... print i # Return values

34. Task
• Write a python program with a dictionary variable with key as
English word and value as meaning of the word.
• User should be able to give an input value which must be checked
whether exist inside the dictionary or not and if it is there print
the meaning of that word

35. Sets

36. Sets
• Sets are unordered collections of unique (non duplicate) elements.
– St= set(‘baabtra calicut’)
– print (st) #prints {‘r’,’u’,’t’,’c’,’b’,’a’,’i’,’l’}

37. Operation on sets
• st1=set(‘baabtracalicut’)
• st2=set(‘baabtra’)
– st1.issubset(st2) #Returns true
– st2.issuperset(st1) #Returns true
– st1. remove(‘mentoringpartner')
– st1. remove(‘calicut)

38. Questions?
“A good question deserve a good grade…”