列表生成式

Posted 2021-03-10 liuhuacai

a = [x * x for x in range(1, 11)]  ##[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
b = [x * x for x in range(1, 11) if x % 2 == 0]  ##[4, 16, 36, 64, 100]
c = [x if x % 2 ==0 else -x for x in range(1,11)] ##[-1, 2, -3, 4, -5, 6, -7, 8, -9, 10]
d = [m + n for m in ‘ABC‘ for n in ‘XYZ‘] ##[‘AX‘, ‘AY‘, ‘AZ‘, ‘BX‘, ‘BY‘, ‘BZ‘, ‘CX‘, ‘CY‘, ‘CZ‘]
dict = {‘x‘:‘A‘,‘y‘:‘B‘,‘z‘:‘C‘}
e = [k + ‘=‘ + v for k,v in dict.items()]  ##[‘x=A‘, ‘y=B‘, ‘z=C‘]
print(a, b, c,d,e)

说明：内容来自于廖雪峰https://www.liaoxuefeng.com/wiki/1016959663602400/1017317609699776。

简单总结：列表解析式大致由以上几种用法。

1.取值

2.过滤取值（后if）

3.取值判断（前 if..else..）

4.取双值