排序IPv4Network和IPv6Network对象的列表

Question

我有一个用IPv4创建的IPv6和ipaddress.ip_network()网络列表，我想对它们进行排序(先按家庭排序，然后再按值排序)。做这件事最好的方法是什么？显然，天真的一种是行不通的：

>>> from ipaddress import ip_network
>>> L = [ip_network(x) for x in ['ff00::/8', 'fd00::/8', '172.16.0.0/12', '10.0.0.0/8']]
>>> L.sort()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.5/ipaddress.py", line 652, in __lt__
    self, other))
TypeError: 10.0.0.0/8 and fd00::/8 are not of the same version

Answer 1

只需使用允许先按类型比较值的 function，如下所示：

>>> from ipaddress import ip_network, IPv6Network
>>> L = [ip_network(x) for x in ['ff00::/8', 'fd00::/8', '172.16.0.0/12', '10.0.0.0/8']]
>>> L.sort(key=lambda x: (isinstance(x, IPv6Network), x))
>>> L
[IPv4Network('10.0.0.0/8'), IPv4Network('172.16.0.0/12'), IPv6Network('fd00::/8'), IPv6Network('ff00::/8')]