python魔法函數的一些疑問

標籤：

看了魔法函數，有一點疑問。1中需要用self.word才能執行，而2直接用self就可以執行。而1中Word繼承了int基本類型，但在__new__時並沒有什麼卵用。當用

Word(“123”)來執行個體化時，看到的運算結果是以字串形式來進行運算的，比如“123”*3=123123123。

1.

class Word(int):    def __new__(cls, word):        word = int(word)        return int.__new__(cls,word)    def __init__(self,word):        self.word = word    def __add__(self, other):        return self.word+other    def __sub__(self,other):        return self.word-other    def __mul__(self, other):        return self.word*other    def __div__(self, other):        return sself.word/otherdef main():    a=Word(123)    b=Word(12)    print a-bif __name__ == ‘__main__‘:    main()

2.

class Word(str):    def __new__(cls, word):        word = word.replace(" ","")        return str.__new__(cls,word)    def __init__(self,word):        self.word = word    def __gt__(self, other):        return len(self)>len(other)    def __lt__(self,other):        return len(self)<len(other)    def __ge__(self, other):        return len(self)>=len(other)    def __le__(self, other):        return len(self)<=len(other)    def __eq__(self, other):        return len(self)==len(other)def main():    a=Word("foorrrdd")    b=Word("sswwss")    print a==bif __name__ == ‘__main__‘:    main()

 

python魔法函數的一些疑問