1实践 ::1,代表本身 ::-1,代表从后往前截取 再比如: a = (1,3,5) print(a[::1]) print(a[::-1]) print(a[::2]) print(a[::-2]) output: (1, 3, 5) (5, 3, 1) (1, 5) (5, 1) 2 其他链接 matlab 冒号用法;