List Comprehensions

It is often useful to create a list with particular content, perhaps based on another list or iterable. It is possible to do this using a loop, or, perhaps, a map function.

List comprehensions provide an alternative that is more declarative than a loop and often clearer than using a map function.

In addition to list comprehensions, there are similar techniques for generating lazy iterators (generator comprehensions), sets, and dictionaries, which we will also cover in this chapter.

List comprehension examples

To start with a simple example, suppose we want to create a list of length 100, filled with the strings, '0’ to ‘99’. There are several ways to do this. Firstly, we ...