27 lines
644 B
Markdown
27 lines
644 B
Markdown
---
|
|
title: Compose functions
|
|
tags: function
|
|
cover: blog_images/tram-car-2.jpg
|
|
firstSeen: 2020-01-02T15:51:20+02:00
|
|
lastUpdated: 2020-11-02T19:27:07+02:00
|
|
---
|
|
|
|
Performs right-to-left function composition.
|
|
|
|
- Use `functools.reduce()` to perform right-to-left function composition.
|
|
- The last (rightmost) function can accept one or more arguments; the remaining functions must be unary.
|
|
|
|
```py
|
|
from functools import reduce
|
|
|
|
def compose(*fns):
|
|
return reduce(lambda f, g: lambda *args: f(g(*args)), fns)
|
|
```
|
|
|
|
```py
|
|
add5 = lambda x: x + 5
|
|
multiply = lambda x, y: x * y
|
|
multiply_and_add_5 = compose(add5, multiply)
|
|
multiply_and_add_5(5, 2) # 15
|
|
```
|