Python：从内置类型继承

我有一个关于内置类型的子类型及其构造函数的问题。我希望一个类同时从元组和自定义类继承

让我给你举个具体的例子。我经常处理图形，这意味着节点与边相连。我开始在自己的图形框架上做一些工作

有一个类Edge，它有自己的属性和方法。它还应该继承自类GraphiElement。（GraphiElement是在特定图形的上下文之外没有意义的每个对象。）但在最基本的层次上，边只是包含两个节点的元组。如果你能做到以下几点，那就太好了：

edge = graph.create_edge("Spam","Eggs")
(u, v) = edge

所以（u，v）将包含“垃圾邮件”和“鸡蛋”。它还将支持类似的迭代

for node in edge: ...

我希望您了解我为什么要对tuple（或set等其他基本类型）进行子类型化

下面是我的Edge类及其init：

class Edge(GraphElement, tuple):

def __init__(self, graph, (source, target)):
    GraphElement.__init__(self, graph)
    tuple.__init__((source, target))

当我打电话时

Edge(aGraph, (source, target))

---

我得到一个TypeError:tuple（）最多接受1个参数（给定2个）。我做错了什么？

因为元组是不可变的，所以您也需要重写uu新的u方法。看

---

您需要覆盖

\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

class GraphElement:
    def __init__(self, graph):
        pass

class Edge(GraphElement):
    def __init__(self, graph, (source, target)):
        GraphElement.__init__(self, graph)
        self.source = source
        self.target = target

    def __iter__(self):
        yield self.source
        yield self.target

在这种情况下，两种用法都很好：

e = Edge(None, ("Spam","Eggs"))
(s, t) = e
print s, t
for p in e:
    print p

我懂了。这确实会给我所有我想要的语法细节。这似乎是更好的解决方案，谢谢。
e = Edge(None, ("Spam","Eggs"))
(s, t) = e
print s, t
for p in e:
    print p