As we saw in Chapter 10, The Functools Module, many algorithms can benefit from memoization. We'll start with a review of some previous examples to characterize the kinds of functions that can be helped with memoization.
In Chapter 6, Recursions and Reductions, we looked at a few common kinds of recursions. The simplest kind of recursion is a tail recursion with arguments that can be easily matched to values in a cache. If the arguments are integers, strings, or materialized collections, then we can compare arguments quickly to determine if the cache has a previously computed result.
We can see from these examples that integer numeric calculations, such as computing factorial or locating a Fibonacci number, will be obviously improved. Locating prime factors and raising integers to powers are more examples of numeric algorithms that apply to integer...