28 lines
634 B
Markdown
28 lines
634 B
Markdown
---
|
|
title: Reverse compose functions
|
|
type: snippet
|
|
language: python
|
|
tags: [function]
|
|
cover: lavender-shelf
|
|
dateModified: 2020-11-02T19:27:07+02:00
|
|
---
|
|
|
|
Performs left-to-right function composition.
|
|
|
|
- Use `functools.reduce()` to perform left-to-right function composition.
|
|
- The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.
|
|
|
|
```py
|
|
from functools import reduce
|
|
|
|
def compose_right(*fns):
|
|
return reduce(lambda f, g: lambda *args: g(f(*args)), fns)
|
|
```
|
|
|
|
```py
|
|
add = lambda x, y: x + y
|
|
square = lambda x: x * x
|
|
add_and_square = compose_right(add, square)
|
|
add_and_square(1, 2) # 9
|
|
```
|