Communicating with Clips rules engine in Python

Question

I would like to communicate several times with Clips rule engine in Python 3.8.3.

For example, I would like to have the following communication

Launch Clips

    C:\Users\username\Clips>"C:\Program Files\CLIPS 6.31\CLIPSDOS64.exe"
             CLIPS (6.31 6/12/19)

Define rules

    (defrule ValueManipulation
      (value ?v)
    =>
      (assert (result ?v))
    )

Query with first fact set and read results from stdout

    (deffacts f1 "My facts" (value 1))
    (reset)
    (run)
    (facts)

Query with second fact set and read results from stdout

    (deffacts f1 "My facts" (value 2))
    (reset)
    (run)
    (facts)

Exit

    (exit)

I have managed to input to stdin once and read from stdout once:

import subprocess

clips_commands = """
(defrule ValueManipulation
  (value ?v)
=>
  (assert (result ?v))
)
(deffacts f1 "My facts" (value 1))
(reset)
(run)
(facts)
(exit)
"""
p = subprocess.Popen('"C:\Program Files\CLIPS 6.31\CLIPSDOS64.exe"', 
                     stdin=subprocess.PIPE, stdout=subprocess.PIPE)
result = p.communicate(input=bytes(clips_commands,'utf-8'))

for line in str(result[0]).split('\\r\\n'):
    print(line)

However, I would like the following kind of query several times and read the output from stdout

    (deffacts f1 "My facts" (value 3))
    (reset)
    (run)
    (facts)

Using packages like pyclips or clipspy was not preferred in the above example, because these packages were not available with pip install. However, repackaging one of these packages could solve the question.

It is not clear what is the issue at hand. What is the problem with the presented method? What is you are trying to achieve? What is the reason you prefer using `subprocess` instead of the libraries? — noxdafox, Sep 21 '20 at 16:35
The libraries do not "pip install". Therefore I am trying to learn communicate with `CLIPSDOS64.exe`. — Heikki, Sep 21 '20 at 18:26
I just built `clipspy` for Python 3.8. You can give it a try. — noxdafox, Sep 21 '20 at 20:43
Thank you @noxdafox ! Reusing rules with clipspy library seems to be at least 20 times faster than the individual `CLIPSDOS64.exe` calls without reusing rules. — Heikki, Sep 22 '20 at 05:53
Edited the question to allow repackaging `clipspy` as a solution. — Heikki, Sep 22 '20 at 06:23

score 0 · Answer 1 · answered Sep 22 '20 at 05:56

Thanks to @noxdafox, I was able to use clipspy library!

Below is the test code which demonstrates reusing clips rules:

import clips

env = clips.Environment()

rule = """
(defrule ValueManipulation
  (value ?v)
=>
  (assert (result ?v))
)
"""
env.build(rule)

print('Add fact 1:')
env.assert_string("(value 1)")
for fact in env.facts():
    print(fact)
env.run()
print('\nResult for fact 1:')
for fact in env.facts():
    print(fact)

print('\nFacts after reset:')
env.reset()
for fact in env.facts():
    print(fact)
env.assert_string("(value 2)")

print('\nResult for fact 2:')
env.run()
for fact in env.facts():
    print(fact)

print('\nResult for fact 3:')
env.reset()
env.assert_string("(value 3)")
env.run()
for fact in env.facts():
    print(fact)

The above code produces the following results:

Add fact 1:
(initial-fact)
(value 1)

Result for fact 1:
(initial-fact)
(value 1)
(result 1)

Facts after reset:
(initial-fact)

Result for fact 2:
(initial-fact)
(value 2)
(result 2)

Result for fact 3:
(initial-fact)
(value 3)
(result 3)

Communicating with Clips rules engine in Python

1 Answers1