List comprehension

Definition

List comprehension is a concise way to create lists in Python using a single line of code. It consists of brackets containing an expression followed by a for clause and optionally, one or more if clauses.

5 Must Know Facts For Your Next Test

1. List comprehensions provide a syntactically compact way to generate lists.
2. The basic syntax includes brackets, an expression, and a for loop: [expression for item in iterable].
3. You can add conditional logic with an if statement: [expression for item in iterable if condition].
4. List comprehensions are generally faster than traditional for loops because they are optimized for performance.
5. They can be nested to handle complex list creation scenarios: [[expression for item in iterable] for sublist in outer_iterable].

Review Questions

• What is the basic syntax structure of a list comprehension?
• How can you add conditions to list comprehensions?
• Why are list comprehensions usually faster than traditional loops?

Related terms

For Loop: A control flow statement that repeatedly executes a block of code as long as the specified condition is true.

Iterable: An object capable of returning its members one at a time, such as lists, tuples, and strings.

Lambda Function: A small anonymous function defined with the lambda keyword that can have any number of arguments but only one expression.