Using map() with multiple sequences

Sometimes, we'll have two collections of data that need to parallel 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 this:

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 like this:

(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 this:

def star_map(function, *iterables)
    return (function(*args) for args in zip(*iterables))

There is a better approach that is already available to us. We don't actually need these techniques. Let's look at a concrete example of the alternate approach.

In Chapter 4, Working with Collections...