for () loop is a counting loop and repeats its body for a pre-defined number of times. It is a very versatile statement and has many forms.
Syntax:
for <variable> in <sequence>:
Here <variable> is a variable that is used for iterating over a <sequence>. All iteration it takes the next value from <sequence> until the last of series is reached.
Example:
1. Write a program to print first 20 even numbers.
Program:
for i in range (1,11):
b=2*i
print(b)
i=i+1
Output:
2
4
6
8
10
12
14
16
18
20
2. Write python Program to print squares of all numbers present in a list.
Program:
num = [1, 2, 3, 4, 5]
sq = 0
for i in range num:
sq = i*i
print(sq)
Output:
1
4
9
16
25
3. Write Python for loop example using range () function
Program:
Program to print the sum of first 3 natural numbers
sum = 0
for i in range(1, 4):
sum = sum + i
print(sum)
Output:
6
4. Write a program print all even numbers between 50 and 100 included both.
Program:
for i in range (50,101):
if i%2==0:
print("The even number is",i)
i=i+1
Output:
The even number is 50
:
:
:
:
The even number is 100
5.Write a program to calculate and print the following series 1,4,9,16,25,....20 terms.
Program:
for i in range (1,21):
print(i*i)
Output:
1
4
9
16
25
:
:
400
6. Write a program to print will numbers between 30-70 which are divisible by 3.
Program:
for i in range (30,70,3):
if i%3==0:
print(i)
i=i+3
Output:
30
33
36
:
:
69
7. Write a program to print all the prime numbers between 1 to 100.
Program:
for i in range (2,100):
for j in range (2,i):
if i%j==0:
break
else:
print(i)
Output:
2
3
5
7
11
:
:
97
For loop with else block
for i in range(5):
print(i)
else:
print("The loop has completed execution")
Output:
0
1
2
3
4
The loop has completed execution
Nested For loop in Python
When a for loop is present inside another for loop then it is called a nested for loop.
for i in range(3):
for j in range(9, 13):
print(i, ",", j)
Output:
0 , 9
0 , 10
0 , 11
0 , 12
1 , 9
1 , 10
1 , 11
1 , 12
2 , 9
2 , 10
2 , 11
2 , 12
For Loop Program Video in Python: