小编Leo*_*oDT的帖子

码:

class Node:
    def __init__(self, key, children=[]):
        self.key = key
        self.children = children

    def __repr__(self):
        return self.key

执行:

root = Node("root")
child = Node("child")
root.children.append(child)
print child.children
print root.children[0].children

结果:

[child]
[child]

这真的很奇怪,为什么？

Python的版本是2.7.2.