python bijection

[M.-A. Lemburg]

geremy condra wrote:
> On Thu, Dec 3, 2009 at 12:57 PM, M.-A. Lemburg <mal at egenix.com> wrote:
>> geremy condra wrote:
>>> On Thu, Dec 3, 2009 at 7:04 AM, M.-A. Lemburg <mal at egenix.com> wrote:
>>>> I think the only major CS data type missing from Python is some
>>>> form of (fast) directed graph implementation à la kjGraph:
>>>>
>>>>    http://gadfly.sourceforge.net/kjbuckets.html
>>>>
>>>> With these, you can easily build all sorts of relations between
>>>> objects and apply fast operations on them. In fact, it should then
>>>> be possible to build a complete relational database in Python
>>>> (along the lines of Gadfly).
>>>
>>> If you're in the market for a Python graph library, you may want
>>> to check out Graphine- I'm obviously biased (I wrote most of it)
>>> but it has a few more bells and whistles than kjbuckets, and is
>>> pretty darned easy to use. It also supports undirected and
>>> bridge graphs.
>>
>> Thanks for the hint :-)
>>
>> The lib looks nice and would probably serve as a good prototype
>> for writing a new built-in type for Python.
> 
> I suspect that it would have a better chance at getting into
> collections than becoming a builtin, but who knows. I'd just
> like to have something like it in the standard library.

Integrating an easy-to-use graph library into the collections
module (and it's C companion) is good idea.

>> This would have to be written in C, though,
> 
> That's currently in the works, along with database backing.
> We'd welcome any help though... hint, hint...
> 
>> and come under a Python compatible license.
> 
> I'm willing to dual license under the Python license if
> there were a substantial interest in doing so, and I'm
> confident that the other authors and maintainers
> would feel the same way.

Great !

> The question in my mind is whether such an interest exists.

Since Python is being used more and more in CS classes,
such an addition would complete the tool-set and make Python
even more attractive for undergrad CS courses.

Finding out how much interest exists in advance is always
a bit difficult with new data-structures. People have to
get a feeling of how they can be put to good use first,
so it's a chicken-and-egg problem.

We've seen the same thing happen with sets. They were first
made available via a separate module and then became built-ins
after people realized how useful they are in practice.

With graphs, it's probably going to take a little longer
before people realize their usefulness - graph theory is
certainly a lot more complicated than set theory :-)

>> With the built-in feature moratorium
>> currently in place, there's about 1.5-2 years time to get this
>> done; perhaps a good GSoC project for next year :-)
> 
> I'd love to have Graphine be a GSoC project, although
> if the target were to get it into collections the
> moratorium wouldn't change the timeline AFAICS.

True.

-- 
Marc-Andre Lemburg
eGenix.com

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