Python for loop increment by multiplication

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For loops, in general, are used for sequential traversal. It falls under the category of definite iteration. Definite iterations mean the number of repetitions is specified explicitly in advance. But have you ever wondered, what happens, if you try to increment the value of the iterator from inside the for loop. Let’s see with the help of the below example.
Example:
 

Python3

lis = [1, 2, 3, 4, 5]

for i in range(len(lis)):

    print(lis[i])

    i += 2

Output:
 

1
2
3
4
5

The above example shows this odd behavior of the for loop because the for loop in Python is not a convention C style for loop, i.e., for (i=0; i 

• Using While loop: We can’t directly increase/decrease the iteration value inside the body of the for loop, we can use while loop for this purpose.
  Example:
   

Python

lis = [1, 2, 3, 4, 5]

i = 0

while(i < len(lis)):

    print(lis[i], end = " ")

    i += 2

• Output: 
   

1 3 5

•  
• Using another variable: We can use another variable for the same purpose because after every iteration the value of loop variable is re-initialized.
  Example: 
   

Python

lis = [1, 2, 3, 4, 5]

i = 0

for j in range(len(lis)):

    if(i >= len(lis)):

        break

    print(lis[i], end = " ")   

    i += 2

• Output: 
   

1 3 5

•  
• Using Range Function: We can use the range function as the third parameter of this function specifies the step.
  Note: For more information, refer to Python range() Function.
  Example:
   

Python3

lis = [1, 2, 3, 4, 5]

for i in range(0, len(lis), 2):

    print(lis[i], end = " ")   

• Output:
   

1 3 5