loop variable python code example

Example 1: python return iteration number of for loop

# Basic syntax:
for iteration, item in enumerate(iteratable_object):
	print(iteration)
# Where:
#	- item is the current element in the iteratable_object
#	- iteration is the iteration number/count for the current iteration

# Basic syntax using list comprehension:
[iteration for iteration, item in enumerate(iteratable_object)]

# Example usage:
your_list = ["a", "b", "c", "d"]

for iteration,item in enumerate(your_list):
	(iteration, item) # Return tuples of iteration, item
--> (0, 'a')
	(1, 'b')
	(2, 'c')
	(3, 'd')

[iteration for iteration, item in enumerate(your_list)]
--> [0, 1, 2, 3]

Example 2: python for loop iterator

import numpy as np
# With array cycling
arr = np.array([1,2,3,4,5,6,7,8,9])

for i in range(len(arr)):
 # logic with iterator use (current logic replaces even numbers with zero)
    if arr[i] % 2 == 0: arr[i] = 0

print(arr)
# Output: [1, 0, 3, 0, 5, 0, 7, 0 , 9]