Alexandre.Fayolle at logilab.fr
Fri Jun 7 12:50:52 EDT 2002
Logilab has released constraint-0.2.
The constraint package is an extensible Constraint Satisfaction Problem
(CSP) solver using constraint propagation algorithms written in 100%
pure Python (tested with Python 2.1)
You can download it from ftp://ftp.logilab.org/pub/constraint/, read a
bit more about it on
and discuss it on the logic-sig mailing list (see
http://lists.logilab.org/mailman/listinfo/python-logic to subscribe)
The package is still young, but we find it useful enough right now, so I
thought I might as well publish it.
What can it do?
* solve some finite-domain CSP
* handle n-ary constraints
How can you extend it:
* by implementing new Domain classes
* by implementing new constraint classes
* by implementing new Distributor classes
How well does it perform?
* 8-queens problems solved in 15 seconds on my 1GHz PC
* SEND+MORE=MONEY problem solved in 8 seconds on the same machine
What has changed?
* a BasicConstraint class was added (these constraint affect only a single
variable, and can be entailed in one pass), with several example
* The Repository class was refactored, and a Solver class was added as
a result, which gives a better separation of the solving logic and
If you're interested by constraint propagation programming in python,
please join the logic-sig mailing list.
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