Sometimes, we'll have two collections of data that need to be parallel to each other. In Chapter 4, Working with Collections, we saw how the zip() function can interleave two sequences to create a sequence of pairs. In many cases, we're really trying to do something like the following:
map(function, zip(one_iterable, another_iterable))
We're creating argument tuples from two (or more) parallel iterables and applying a function to the argument tuple. We can also look at it as follows:
(function(x,y) for x,y in zip(one_iterable, another_iterable))
Here, we've replaced the map() function with an equivalent generator expression.
We might have the idea of generalizing the whole thing to the following:
def ...
