python bijection

[geremy condra]

On Fri, Dec 4, 2009 at 7:42 PM, Lie Ryan <lie.1296 at gmail.com> wrote:
> On 12/5/2009 9:41 AM, Carl Banks wrote:
>>
>> On Dec 4, 12:46 pm, geremy condra<debat... at gmail.com>  wrote:
>> more common than full-blown graph package).
>>>
>>> Sure, its a tree, which is also a graph. In this case it looks to
>>> me more like a directed acyclic graph than anything, but its
>>> pretty much just semantics since the interface is functionally
>>> equivalent.
>>
>> I'd have to agree with Lie, yes a tree is a graph, but it's simply not
>> an argument that Python community is grasping for graph structures.
>> It's like arguing that the Python community could benefit from a
>> quaternion type, because quaternions are actually heavily used in
>> Python, because a scalar number is a quarternion.
>
>>
>>
>> Carl Banks
>>
>> (Would be +1 on a good graph implementation... just not because of
>> ElementTree.)
>
> I think this could be an interpretation of the Zen:
>
> Simple is better than complex.
> Complex is better than complicated.
>
> can be read as:
> List is better than Tree
> Tree is better than Graph
>
> not having Tree and Graph package in the standard library force most people
> to find List-based solution. And people that know they need graphs will find
> them in 3rd party modules. I have needed Trees a few times in python, but
> very rarely a Graph (except for playing around). YMDWV (your mileage
> definitely will vary).

Where a list will do, use a list- duh. But when you need a graph, you
shouldn't have to homebrew an implementation any more than you
should have to homebrew an odict or named tuple, both of which
are substantially easier to get right than a graph is.

Geremy Condra