问题描述
有没有一种简单快捷的方法来使用非整数值的 sum()?
Is there a simple and quick way to use sum() with non-integer values?
所以我可以这样使用它:
So I can use it like this:
class Foo(object): def __init__(self,bar) self.bar=bar mylist=[Foo(3),Foo(34),Foo(63),200] result=sum(mylist) # result should be 300
我尝试覆盖 __add__ 和 __int__ 等,但我还没有找到解决方案
I tried overriding __add__ and __int__ etc, but I don't have found a solution yet
解决办法是实现:
def __radd__(self, other): return other + self.bar
正如威尔在他的帖子中所建议的那样.但一如既往,条条大路通罗马,但我认为这是最好的解决方案,因为我的课堂不需要 __add__
as Will suggested in his post. But as always, all roads lead to Rome, but I think this is the best solution since I don't need __add__ in my class
推荐答案
这有点棘手 - sum() 函数获取开始并将其添加到下一个等等
Its a bit tricky - the sum() function takes the start and adds it to the next and so on
你需要实现 __radd__ 方法:
class T: def __init__(self,x): self.x = x def __radd__(self, other): return other + self.x test = (T(1),T(2),T(3),200) print sum(test)