First-class functions

Functions are values like any other - they can be named, passed to other functions, returned and stored - which lets one function hold a pattern of work and take the details from outside.

Depth 1 · Foundation

You can pass a function as a value - a key to sorted, max and min, a lambda, a function to map and filter or to your own function - and you know the difference between len and len().

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Depths of understanding

1
Foundation
You can pass a function as a value - a key to sorted, max and min, a lambda, a function to map and filter or to your own function - and you know the difference between len and len().
Opens after
ListsMost functions that take functions, like sorted and map, work on a list, so lists come first.Functions in codePassing a function around only makes sense once you can define and call one.
2
Deeper
You can write a function that makes and returns another function, explain how a closure keeps the names it was made with (and when nonlocal is needed), and write a decorator that wraps any function.
Master depth 1 first
ScopeA closure is a function that keeps the local names of the function it was made in, so you need to know how local names work first.

Your path here

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Where it fits

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ListsData Structures Functions in code

This concept

First-class functionsFunctions

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ComprehensionsData Structures SortingAlgorithms

Builds onThis conceptOpens upListsData Structures Functions in code First-class functionsFunctions ComprehensionsData Structures SortingAlgorithms