python 高阶函数简单介绍

abs(-10) # 10

round(1.2) # 1
round(1.9) # 2

def add_num(a, b):
  return abs(a) + abs(b)


result = add_num(-1, 2)
print(result) # 3

def sum_num(a, b, f):
  return f(a) + f(b)


result = sum_num(-1, 2, abs)
print(result) # 3

list1 = [1, 2, 3, 4, 5]


def func(x):
  return x ** 2


result = map(func, list1)

print(result) # <map object at 0x0000013769653198>
print(list(result)) # [1, 4, 9, 16, 25]

import functools

list1 = [1, 2, 3, 4, 5]


def func(a, b):
  return a + b


result = functools.reduce(func, list1)

print(result) # 15

list1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]


def func(x):
  return x % 2 == 0


result = filter(func, list1)

print(result) # <filter object at 0x0000017AF9DC3198>
print(list(result)) # [2, 4, 6, 8, 10]