Track 6 · Lesson 9 of 12

Comprehensions: building collections in one line

Write list, dict and set comprehensions with filters, and know when a plain loop is clearer.

You will be able to

• Rewrite a build-a-list loop as a list comprehension
• Filter items with an if clause and transform them with an expression
• Build dictionaries and sets with dict and set comprehensions
• Recognise when a comprehension hurts readability and a loop is better