剑指offer python版 滑动窗口的最大值

def aa(nums,s):
    i=0
    leng=len(nums)
    ret=[]
    while i<leng-s+1:
        ret.append(max(nums[i:i+s]))
        i +=1
    return ret


print(aa([2,3,4,2,6,2,5,1],3))