[Python-Dev] Issues with Py3.1's new ipaddr

["Martin v. Löwis"]

> Clay is basically correct.  The ipaddr.py API is missing important
> features, and it would probably be a mistake to add it to the python
> standard library if that means we'd have to maintain compatibility for
> the indefinite future.

>From a maintenance point of view, these two statements don't really
relate. Yes, adding it to the standard library means that compatibility
must be maintained (not for the indefinite future, but in a very strong
sense). But no, that doesn't mean that it cannot have new features.

Adding new features would not have to break compatibility, and, in
many real-world cases of existing libraries, didn't.

For the net-vs-host issue, I think a backwards-compatible solution
is possible: just give the IP() function an option parameter that
makes it reject a netmask during parsing.

> Like all largeish python projects, we wrote a library to do IP address
> manipulation.  In our case, it's a whopping 64 lines long.
[...]
> In fact, if I was starting a new project from scratch with similar
> requirements, I'd probably write my own library instead of using ipaddr.

That was my feeling as well when ipaddr was first offered. It's just
not an important library, and people will continue to roll their own
for some time. OTOH, with ipaddr in the standard library, people will
also start contributing extensions that make it support their use cases,
so it should grow a wider application area than it currently supports.

Regards,
Martin