[Python-Dev] PEP 3144: IP Address Manipulation Library for the Python Standard Library

Antoine Pitrou solipsis at pitrou.net
Wed Aug 26 21:02:28 CEST 2009

Martin v. Löwis <martin <at> v.loewis.de> writes:
> [...]
> Then, class IPAddress has a method reverse_dns, which is defined
> as
>     def reverse_dns(self):
>         """The reverse DNS lookup record for this IP address"""
>         return self._module.int_to_arpa(self._value)
> So IPv4 addresses and IPv6 addresses share the same class, but instances
> have different values of _module.

Ok, thanks for the explanation. It looks like an inheritance-based approach
would allow for easier and more traditional introspection (e.g. `isinstance(ip,
IPv4Address)`). Not to mention that avoiding an indirection level can make
things faster.



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