在python中,strings, 元组tuples, 和numbers是不可更改的对象,而list,dict等则是可以修改的对象。a = 1def fun(a): a = 2fun(a)print a # 1 a = []def fun(a): a.append(1)fun(a)print a # [1] https://github.com/taizilongxu/interview_python