python步进切片

步进切片 sequence[起始索引，结束索引，步进值] l = [1,2,3,4,5,6,7] #反向切片有倒序效果 #步长为1 l[::-1] Out: [7, 6, 5, 4, 3, 2, 1] l[::1] Out: [1, 2, 3, 4, 5, 6, 7] #步长为2 l[::-2] Out: [7, 5, 3, 1] l[::2] Out: [1, 3, 5, 7]