php手机网站模板,东阿县城市建设局网站,免费ppt模板下载包图网,图片展示网站php源码切片赋值
如果把切片放在赋值语句的左边#xff0c;或把它作为del操作的对象#xff0c;我们就可以对序列进行嫁接、切除 或就地修改操作。 l [i for i in range(20)]l
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 1…切片赋值
如果把切片放在赋值语句的左边或把它作为del操作的对象我们就可以对序列进行嫁接、切除 或就地修改操作。 l [i for i in range(20)]l
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]l[2:4][1]l
[0, 1, 1, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]len(l)
19l[2:6:2] [a,b]l
[0, 1, a, 4, b, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]del l[2:6]l
[0, 1, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]del l[2:6:2]l
[0, 1, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]如果切片内带了step参数的值则需要保证右边列表内的元素个数与左边切片内的元素个数相等否则就会报错 l[2::2] [100,200]
Traceback (most recent call last):File stdin, line 1, in module
ValueError: attempt to assign sequence of size 2 to extended slice of size 9
