python operator overload and friends

问题

I wanted to know if anyone could give me an example of how to overload an operator within a class, in my case the + operator. Could I define a function (not a class method) that does it? I'm a newbie so I don't really know how to do it.

Thanks

回答1:

class MyNum(object):
    def __init__(self, val):
        super(MyNum,self).__init__()
        self.val = val

    def __add__(self, num):
        return self.__class__.(self.val + num)

    def __str__(self):
        return self.__class__.__name__ + '(' + str(self.val) + ')'

print(MyNum(3) + 2)   # -> MyNum(5)

回答2:

Define its __add__() method.

See here.

回答3:

When in doubt of the basics: manual. http://docs.python.org/reference/datamodel.html

来源：https://stackoverflow.com/questions/5438574/python-operator-overload-and-friends