python-偏移列表

import math
a=[1,2,3,4,5,6,7,8,9,10]
b=input("输入偏移量：")
if b>=0:
    for i in range(len(a)):
        if i >= b:
            c=a[b:len(a)]
        else:
            c=a.append(a[i])
else:
    c=a[len(a)-abs(b):len(a)]
    for i in range(len(a)-abs(b)):
        c.append(a[i])
print(a,c)