Functional Python Programming - Third Edition

 3 Functions, Iterators, and Generators

The core of functional programming is the use of pure functions to map values from the input domain to the output range. Avoiding side effects reduces any dependence on variable assignment to maintain the state of a computation. We can’t purge the assignment statement from the Python language, but we can reduce our dependence on stateful objects. This means choosing among the available Python built-in functions and data structures to select those that don’t require stateful operations.

This chapter will present several Python features from a functional viewpoint, as follows:

• Pure functions, free of side effects

• Functions as objects that can be passed as arguments or returned as results

• The use of Python’s ...