What exactly are iterator iterable and iteration

Question

What is the most basic definition of "iterable", "iterator" and "iteration" in Python?

Answer 1

Iteration is a process in which one single element is taken at a time given n elements.
Iterable is an object that one iterates over elements,
while iterator is an object that generates values during iteration and is also returned by the iterable object.
Iterable object implements __iter__() method and returns an iterator object.

Python Built-in iterable objects are list, sets, strings,
If __iter__() method does not work then __getitem__() is used.
Iterators implement the __next__() method. This means that the next values are returned until all the values are exhausted. Also the iterator object gets updated.
Let us take an example:

Obj1 = 'Pie'     # Obj1 is an string and also is Iterable

Piece = iter(Obj1)  #Piece is Iterator

next(Piece)

'P'

next(Piece)

'i'

next(Piece)

'e'

next(Piece)

---------------------------------------------------------------------------
StopIteration                             Traceback (most recent call last)
<ipython-input-26-aad7e70238c3> in <module>
----> 1 next(Piece)

StopIteration: