[Python-Dev] PEP 3144 review. (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Sun Sep 27 08:56:40 CEST 2009

As a side note, I would be in favor of dropping the concept of a mask from the library, and only support a prefix length. -1

IPv6 doesn't support masks at all, and even for IPv4, I think there are conventions (if not RFCs) against using them in a way that does not correspond to a prefix length. Then the module should only support netmasks of the form (say) '255.255.255.224' (equivalent to "/27"), and reject those like "255.3.255.255". It currently accepts them. Many applications still display netmasks in dot-quad form, and I would be terribly annoyed if I had to count the bits myself before passing it to IPv4Address.

I wouldn't ask for that: it should certainly be possible to supply masks. However, I would want to reject masks that don't correspond to a prefix, and have only the prefix length in the internal representation.

Regards, Martin

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