Iterators in python are used with a ‘for loop’. code example

Example 1: iterator in python

class PowTwo:
    """Class to implement an iterator
    of powers of two"""

    def __init__(self, max=0):
        self.max = max

    def __iter__(self):
        self.n = 0
        return self

    def __next__(self):
        if self.n <= self.max:
            result = 2 ** self.n
            self.n += 1
            return result
        else:
            raise StopIteration


# create an object
numbers = PowTwo(3)

# create an iterable from the object
i = iter(numbers)

# Using next to get to the next iterator element
print(next(i))
print(next(i))
print(next(i))
print(next(i))
print(next(i))

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]