元组中的元素不能被修改

v1 = (11,22,33)

v1[0] = 666 错误

v1 = (11,(22,33),44)

v1 = (11,22,33,[44,55,66])

v1[-1][1] = 666 

v1=[11,22,(33,44,55)]

v1[-1] = 666