[Tutor] How does this work (iterating over a function)?

[Danny Yoo]

By the way, it may be really instructive to read the article when
generators were officially introduced into Python 2.2:

    https://docs.python.org/3/whatsnew/2.2.html#pep-255-simple-generators

It's written for the perspective of someone who doesn't know what
generators are.  Because of that, it should be fairly approachable.