Pyke: Python Knowledge Engine
Both forward-chaining and backward-chaining rules (which may include python
code) are compiled into python. Can also automatically assemble python
programs out of python functions which are attached to backward-chaining
COPYRIGHT AND LICENSE:
This is published under the MIT License. The copyright and license are in
the file "copyright_license".
The documentation is at:
You can download a copy of this documentation to your hard drive:
See the end of this file for how to regenerate the html files.
Pyke requires python 2.5 (or later 2.x release). Check with:
$ python2.5 --version
or $ python --version
You can download this at:
To install pyke with easy_install, at the shell prompt just type:
$ easy_install-2.5 pyke
If you don't have easy_install, you should install it:
then (as root) run: $ python2.5 ez_setup.py
Otherwise, you'll also need ply 2.3 from:
This can be checked as follows:
>>> from ply import lex
Then you got two choices for pyke:
or the source distribution (see below)
The pyke source distribution is the file:
This contains the pyke source code, documentation (both source and html), and
Pyke examples may be downloaded separately from sourceforge if you've used
easy_install to install pyke (or installed the .egg file):
Each example has a README file that explains how to run it.
The family_relations example is a good place to start. It shows several
solutions to the same problem. It also has an example of a few rule
optimizations that result in a 100 times performance improvement on this
The sqlgen example uses MySQL and the python MySQLdb module. It has a
function that reads the schema information into pyke facts. Then the rules in
database.krb automatically figure out how to join tables together to retrieve
a list of column names, generate the SQL select statement and return a plan to
execute this SQL statement and return the results as a dictionary.
The web_framework example uses the sqlgen example. This demonstrates the use
of multiple rule bases. The web_framework is a WSGI application that uses the
HTMLTemplate package. It gets the column names from the HTMLTemplate and
feeds those to the sqlgen example to generate a plan to retrieve the data. It
then builds a plan to populate the template and return the finished HTML
document. It also caches the plans so that they don't have to be re-generated
for each request. This should make this run very fast! The example includes
a wsgiref simple_server setup to run it as an http server so that you can
access it through your browser.
The findall, forall, knapsack and notany examples are each very small.
TO INSTALL FROM THE SOURCES:
$ python2.5 setup.py install
To run doctests on all *.py files in the pyke directory, cd to the pyke
To run doctests on the whole source directory, cd to the top-level directory
COMPILING THE COMPILER.KRB FILE:
>>> from pyke import krb_compiler
>>> krb_compiler.compile('.', 'compiled_krb', ('compiler.krb',))
$ cp compiled_krb/compiler_bc.py .
$ rm -rf compiled_krb
COMPILING THE DOCUMENTATION:
To compile the documentation into html, you'll need docutils and rest2web.
If you're running linux, your distro may have packages for these already.
Or you can:
$ easy_install-2.5 rest2web
I used version 0.4.1 of docutils and 0.5.0 of rest2web. I don't know if
earlier versions work OK or not.
To check your versions:
>>> import docutils
>>> import rest2web
If your linux distro doesn't have packages for these, and you don't want to
use easy_install, you can get them at:
To regenerate the html, cd to the doc directory and:
$ r2w r2w.ini
This regenerates everything from doc/source into doc/html. It takes about
3 seconds to run.
If you want to run doctest on all of the *.txt files in doc/source,
cd to doc and: