iterators-generators.md

Iterators and Generators

Iterator

Iterator is an object that can be iterated upon. An object which returns data,one element at a time when next() is called on it.

Iterable

An object which will return an Iterator when iter() is called on it.

For example "HELLO" is an iterable but its not an iterator but iter("HELLO") returns an iterator.

NEXT()

When next() is called on an iterator, the iterator returns the next item. It keeps doing so until it raises a StopIteration error.

def custom_iter(iterable):
    iterator = iter(iterable)
    while True:
        try:
            print(next(interator))
        except StopIteration:
            print("END")
            break

Generators

• Generators are iterators.
• Generator can be created with generator functions