(And yes, Python's definition of "everything" isn't as wide as Smalltalk's.) And you'll get the following output ... x*y}" return bar b = foo(10) print(b(2)) Sure enough, this passes Mypy's checks.

A normal Python function, when called ... The thing is that generators as described here produce output, but can't get any input. For example, you could create a generator to return one Fibonacci ...

Because functions are mathematical constructs which perform a calculation and return ... output for a given input (as a side note, you can have only single input functions, and still semantically ...