expertSystem.py

#!/usr/bin/python

import sys
import re
from printcolor import *

Rules = []
Query = ""
Facts = {}

#Parse File	
def removeComment(line):
	index = 0
	if '#' in line:
		index = line.index("#")
		return line[:index]
	return line
	
def parseFile(f):
	#needed to update a global
	global Rules
	global Query
	global Facts

	for line in f:
		if line.startswith('#'):
			continue
		elif line.startswith('?'):
			Query =  removeComment(line)
		elif line.startswith('='):
			facts = removeComment(line)
			for letter in facts:
				if letter.isalpha():
					Facts.update({letter:1})
		elif line:
			Rules.append(removeComment(line))
	printYellow(str(Query))
	printGreen(str(Facts))
	printBlue(str(Rules))

def solve_xor(a, b):
	if a == b:
		return 0
	return 1

def solve_or(a, b):
	if a == 1 or b == 1:
		return 1
	return 0

def solve_and(a, b):
	if a == 1 and b == 1:
		return 1
	return 0

#priority
# ( ) 1	
# ! not 2
# + and 3
# | or 4
# ^ xor 5
# => implies 6 
# <=> if only if 7

def main():
	if len(sys.argv) != 2:
		print("Error: input expected.")
		return
	s = str(sys.argv[1])
	try:
		f = open(s, 'r')
	except IOError as e:
		print("I/O error({0}): {1}".format(e.errno, e.strerror))
		exit()
	parseFile(f)
	f.close()
	print(solve_xor(Facts['A'], Facts['B']))
	print(solve_or(Facts['A'], Facts['B']))
	print(solve_and(Facts['A'], Facts['B']))
	return

main()