pylog

library1.1pypypi✓ verified 24d ago

Pylog is a lightweight Python library that implements core features of Prolog, enabling logic programming paradigms within Python. It allows defining facts and rules to perform simple logical deductions and goal-oriented queries. The current stable version is 1.1, with an infrequent release cadence focusing on stability and minor enhancements.

data

pip install pylog

github ↗package ↗

INSTALL

IMPORT

SIG · PYLOG

pylog

datapythonv1.1

Install

1.6s avg

Import

—

Disk

16MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 0.000s · 17.9MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 1.6s · import 0.000s · 18MB

16MB installed

● package 16MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

name

✓ from pylog import name

✗ from pylog.pylog import facts, rules, goal, run

This quickstart demonstrates how to define facts, create a simple rule using other predicates, set a goal, and retrieve solutions using the `run()` function. It showcases basic logical inference capabilities.

from pylog.pylog import facts, rules, goal, run # Define facts facts("human(socrates)") facts("human(plato)") # Define a rule: All humans are mortal # The body is a list of predicates that must be true for the head to be true. rules("mortal(X)", ["human(X)"]) # Define a goal to find all mortal beings goal("mortal(X)") # Run the inference engine to find solutions solutions = run() print("Solutions for mortal(X):") for s in solutions: print(s) # Example for a specific query goal("mortal(socrates)") solutions_socrates = run() print("\nSolutions for mortal(socrates):") for s in solutions_socrates: print(s)

Debug

Known issues

breakingThe project underwent significant restructuring around versions `1.0`/`1.1` (including the 'test1' release), which changed the import paths for core functions.

fix

Update all import statements. Instead of `import pylog` or `from pylog import symbol`, use `from pylog.pylog import symbol` for functions like `facts`, `rules`, `goal`, and `run`.

affects: <1.0

gotchaPylog heavily relies on global state for its `facts` and `rules` knowledge base. Calls to `facts()` and `rules()` modify a shared global state.

fix

Be aware that the knowledge base is global. For applications requiring isolated logical contexts, manually manage state or consider external mechanisms, as `pylog` does not provide explicit APIs for context management or resetting the knowledge base directly.

affects: All versions

gotchaPylog implements a subset of Prolog's features. It may not support advanced Prolog constructs like complex data structures, explicit cut/fail predicates, or certain types of recursion with optimal performance.

fix

Consult the library's GitHub repository for current capabilities and examples. Do not expect full Prolog compatibility; plan your logic programming tasks accordingly within the library's demonstrated scope.

affects: All versions

Upgrade

Version history

1.1latest on PyPI · released Sep 7, 2019

Audit

Dependencies

No dependency data recorded yet.

Agent activity

16 hits · last 30 days

node

Resources

githubhttps://github.com/RussAbbott/pylog ↗

packagehttps://pypi.org/project/pylog/ ↗