python for loop iterator code example

Example 1: iterator in python

# define a list
my_list = [4, 7, 0, 3]

# get an iterator using iter()
my_iter = iter(my_list)

# iterate through it using next()

# Output: 4
print(next(my_iter))

# Output: 7
print(next(my_iter))

# next(obj) is same as obj.__next__()

# Output: 0
print(my_iter.__next__())

# Output: 3
print(my_iter.__next__())

# This will raise error, no items left
next(my_iter)

Example 2: how to create a break in iterating a sequence with a specific set of values in python

>>> d = {'foo': 1, 'bar': 2, 'baz': 3}
>>> for k, v in d.items():
...     print('k =', k, ', v =', v)
...
k = foo , v = 1
k = bar , v = 2
k = baz , v = 3

Example 3: how to use iteration in python

n = 5
while n > 0:
    print n
    n = n-1
print 'Blastoff!'

Example 4: 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]