Iterators

The object that produces successive items or values from its associated iterable

Technically, in Python, an iterator is an object which implements the iterator protocol, which consist of the methods __iter__() and __next__()

Iterator vs Iterable

Lists, tuples, dictionaries, sets & string are all iterable objects. They are iterable containers which you can get an iterator from

All these objects(Lists, tuples, dictionaries, sets & String) have a iter() method which is used to get an iterator

In below example, return an iterator from a list, and print each value:

mylist = ["one", "two", "three"]
myit = iter(mylist)

print(next(myit))       #Output: one
print(next(myit))       #Output: two
print(next(myit))       #Output: three

Iterator vs For Loop

The for loop actually creates an iterator object and executes the next() method for each loop

Example 1

mylist = ["one", "two", "three"]

for x in mylist:
    print(x)

one
two
three

Example 1

mylist = ["one", "two", "three"]
myit = iter(mylist)

for x in myit:
    print(x)

one
two
three

Above both examples displays the same output since 'for' loop and 'iter' & 'next' methods are iterate through\from an iterable object

let's do a quick review these terms

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