python – 如何在我的课堂上赋予字符串？

>>> class A(str):
...    def __new__(cls,color,*args,**kwargs):
...        newobj = str.__new__(cls,**kwargs)
...        newobj.color = color
...        return newobj
>>> a = A("#fff","horse")
>>> a.color
'#fff'
>>> a
'horse'
>>> a.startswith("h")
True