Python Simple decision table procesor

Install

pysidetap is available on PyPI pypi-pysidetap and you can install it using pip:

`sh pip install pysidetap `

Summary

Simple Decision Table Processor

https://en.wikipedia.org/wiki/Decision_table

This function find and return field ‘return’ from Decision Table,

when all operands in row by ‘fields’ are True.

Example:

This example show use case off Traffic lights decisions.

https://en.wikipedia.org/wiki/Traffic_light#Meanings_of_signals

Decision Table:

red	yellow	green	return
==on	==off	==off	stop
==on	==on	==off	ready
==off	==off	==on	go
==off	==on	==off	break
==off	==off	==off	off

from pysidetap.processor import DTProcessor

DTableTL = [
    {
        'fields': {
            'red': {'op':'==', 'value':'on'},
            'yellow': {'op':'==', 'value':'off'},
            'green': {'op':'==', 'value':'off'},
        },
        # Traffic may not proceed beyond the stop line or
        # otherwise enter the intersection
        'return': {'stop'}
    },
    {
        'fields': {
            'red': {'op':'==', 'value':'on'},
            'yellow': {'op':'==', 'value':'on'},
            'green': {'op':'==', 'value':'off'},
        },
        # The signal is about to change, but the red light rules do apply
        'return': {'ready'}
    },
    {
        'fields': {
            'red': {'op':'==', 'value':'off'},
            'yellow': {'op':'==', 'value':'off'},
            'green': {'op':'==', 'value':'on'},
        },
        # Traffic may not pass the stop line or enter the intersection
        # unless it cannot safely stop when the light shows
        'return': {'go'}
    },
    {
        'fields': {
            'red': {'op':'==', 'value':'off'},
            'yellow': {'op':'==', 'value':'on'},
            'green': {'op':'==', 'value':'off'},
        },
        # Traffic may proceed unless it would not clear the intersection
        # before the next change of phase
        'return': {'break'}
    },
    {
        'fields': {
            'red': {'op':'==', 'value':'off'},
            'yellow': {'op':'==', 'value':'off'},
            'green': {'op':'==', 'value':'off'},
        },
        # Traffic lights is off
        'return': {'off'}
    },
]

p = DTProcessor(DTableTL)
for red in ['on','off']:
    for yellow in ['on','off']:
        for green in ['on','off']:
            result = p.process({'red':red, 'yellow':yellow, 'green':green})
            print(f'red: {red}, yellow: {yellow}, green: {green}, result:{result}')

Issues and Discussions

As usual for any GitHub-based project, raise an issue if you find any bug or want to suggest an improvement, or open a discussion if you want to discuss or chat :wink:

Version

v0.0.4