Clean Code in Python

The interface for iteration

An iterable is an object that supports iteration, which, at a very high level, means that we can run a for .. in ... loop over it, and it will work without any issues. However, iterable does not mean the same as iterator.

Generally speaking, an iterable is just something we can iterate, and it uses an iterator to do so. This means that in the __iter__ magic method, we would like to return an iterator, namely, an object with a __next__() method implemented.

An iterator is an object that only knows how to produce a series of values, one at a time, when it's being called by the already explored built-in next() function. While the iterator is not called, it's simply frozen, sitting idly by until it's called again for ...