If you’ve ever written any Python at all ... The for loop we wrote above expected an iterable. When __iter__ is called on an object, it must return an iterator. That iterator can be an external ...

In the early days of C, you’d occasionally see someone — probably a former Pascal programmer — write something like this: #define BEGIN { #define END ... for loop inside of Python.

In the following example, we loop through a list of numbers, and use the variable digit to hold each number in turn: Strings in Python are considered “sequences” — they can be iterated over ...