[开发工具]python中reduce、map、zip、filter的用法

1、python中reduce、map、zip、filter的用法

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2021/9/18 14:34
# @Author  : 小梁同学@0311
# @File    : cs_007.py
# @Software: PyCharm


# reduce  多个进一个出
from functools import reduce

lis = [1, 2, 3, 4, 5, 6]
res = reduce(lambda x, y: x + y, lis)
# res = reduce(lambda x, y: x + y, lis, 100)
print(res)

lis2 = ['1', '2', '3', '4', '5', '6', '7']
res = '|'.join(lis2)  # 拼接的列表里的元素 必须是字符串
print(res)

# map  映射
lis3 = [1, 2, 3, 4, 5]
res = map(lambda x: x ** 2, lis3)
print(list(res))

# zip  拉链
l1 = [111, 222, 333, 444, 555]
l2 = ['小红', '小黑', '小白']
l3 = [1, 2, 3, 4, 5, 6, 7, 8, ]
res = zip(l1, l2, l3)  # 以最短的为主
print(list(res))

# filter  过滤
l4 = [1, 2, 3, 4, 5, 6, 7, 8]
res = filter(lambda x: x > 3, l4)
print(list(res))  # [4, 5, 6, 7, 8]