[PY] [Lc]python Higher order function (anonymous/map/reduce/sorted)

anonymous functions

f = lambda x: x * xf(2) # x =2#4- 传入列表f = lambda x: x[2]print(f([1, 2, 3])) # x = [1,2,3]

Map using

Incoming function body

def f(x):    return x*xr = map(f, [1, 2, 3, 4]) #函数作用在可迭代对象的每一项#[1, 4, 9, 16]- 另一个例子list(map([1, 2, 3, 4, 5, 6, 7, 8, 9], lambda x: x * x))

Reduce usage

from functools import reducedef add(x, y):    return x*10 + yprint(reduce(add, [1, 2, 3, 4])) #函数作用在可迭代对象的每一项聚合# 1234

Sorted inquiry

Reference:
Higher order function Map/reduce

Sorted, the official document is very good, can learn a lot of things

sorted(iterable, key=None, rev

[PY] [Lc]python Higher order function (anonymous/map/reduce/sorted)