19 lines
430 B
Markdown
19 lines
430 B
Markdown
---
|
|
title: max_by
|
|
tags: math,list,beginner
|
|
---
|
|
|
|
Returns the maximum value of a list, after mapping each element to a value using the provided function.
|
|
|
|
- Use `map()` with `fn` to map each element to a value using the provided function.
|
|
- Use `max()` to return the maximum value.
|
|
|
|
```py
|
|
def max_by(lst, fn):
|
|
return max(map(fn, lst))
|
|
```
|
|
|
|
```py
|
|
max_by([{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }], lambda v : v['n']) # 8
|
|
```
|