[Python-Dev] address manipulation in the standard lib

Duncan McGreggor duncan.mcgreggor at gmail.com
Mon Jan 5 18:10:32 CET 2009

Last Fall, Guido opened a ticket to include Google's ipaddr.py in the
standard lib:

There has been some recent discussion on that ticket, enough so that
it might benefit everyone if it was moved on to the dev list. I do
recommend reading that ticket, though -- lots of good perspectives are

The two libraries that are being discussed the most for possible
inclusion are the following:
  * http://code.google.com/p/ipaddr-py/wiki/IPAddrExmples
  * http://code.google.com/p/netaddr/wiki/NetAddrExamples

The most immediately obvious differences between the two are:
  * ipaddr supports subnet/supernet/net exclusions
  * netaddr supports EUI/MAC address manipulations
  * the netaddr API differentiates between an IP and a CIDR block
  * netaddr supports wildcard notation
  * netaddr supports binary representations of addresses
  * ipaddr is one module whereas netaddr consists of several (as well
as IANA data for such things as vendor lookups on MAC addresses)
  * ipaddr benchmarks as faster than netaddr
  * netaddr is currently PEP-8 compliant

That's a quick proto-assessment based on looking at examples and unit
tests and didn't include a thorough evaluation of the code itself.

Martin provided some very nice guidelines in a comment on the ticket:

"I think Guido's original message summarizes [what we need]: a module
that fills a gap for address manipulations... In addition, it should
have all the organisational qualities (happy user base, determined
maintainers, copyright forms, documentation, tests). As to what
precisely its API should be - that is for the experts (i.e. you) to
determine. I personally think performance is important, in addition to
a well-designed, useful API. Conformance to PEP 8 is also desirable."

I'm planning to chat with both David Moss (netaddr) and Peter Moody
(ipaddr) on the mail lists about API details, and I encourage others
to do this as well. As for this list, it's probably important to
define the limits of the desired feature set for an ip address
manipulation library:
  * do we want to limit it to IP (i.e. no EUI/MAC support)?
  * do we want a single module or is a package acceptable?
  * what features would folks consider essential or highly desirable
(details on this will be discussed on the project mail lists)
  * other thoughts?


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