An example of a method to use a python iterator

What is an iterator?

The iterator is a simple object with a next method, and of course implements the function with the next method. Iterators can iterate over a sequence of values, and when no iteration is available, the next method raises a StopIteration exception. Many objects in python are iterators, such as lists, elements, strings, files, maps, and collections

How to use iterators?

1. For variable in iterable object

    list1 = [1,2,3,4,5]
for ele in list1:
    print ele,

The result is: 1, 2, 3, 4, 5

2. If the variable in can iterate the object

list1 = [1,2,3,4,5]
var = 1
if var in list1:
    print 'yes!'
else:
    print 'No'

3. Variable = iter(iterable object)

it = iter([1,2,3,4])
print it.next()
print it.next()
print it.next()

The result is:

1
2
3

Finally, to summarize: an iterator is an object