Functional Python Programming

Reducing with operators

We'll look at one more way that we might try to use the operator definitions. We can use them with the built-in functools.reduce() function. The sum() function, for example, can be defined as follows:

sum= functools.partial(functools.reduce, operator.add)

We created a partially evaluated version of the reduce() function with the first argument supplied. In this case, it's the + operator, implemented via the operator.add() function.

If we have a requirement for a similar function that computes a product, we can define it like this:

prod= functools.partial(functools.reduce, operator.mul)

This follows the pattern shown in the preceding example. We have a partially evaluated reduce() function with the first argument of * operator, ...