calculator.py

from solvematrix import SolveMatrix
from tuplify import Tuplify
from grind import SolveGrind

class Calculator(object):
    def __init__(self, inputLine):
        if inputLine == "":
            raise ValueError("inputLine cannot be null")
        self.result = None
        self._parse(inputLine)

    def _parse(self, inputLine):
        equation = inputLine.replace('"', '')
        equation = equation.replace("_", "**")

        self.equation = equation

        split = equation.split('=')

        # prepend an explicit + if the lhs or rhs start without one
        lhs = split[0]
        if lhs[0] != '-':
            lhs = "+" + lhs
        rhs = split[1]
        if rhs[0] != '-':
            rhs = "+" + rhs

        # insert spaces
        lhs = lhs.replace("+", " +")
        lhs = lhs.replace("-", " -")
        rhs = rhs.replace("+", " +")
        rhs = rhs.replace("-", " -")

        self.args = []

        lhsItems = lhs.split()
        for e in lhsItems:
            self.args.append(Tuplify(e))
        rhsItems = rhs.split()
        for e in rhsItems:
            self.args.append(Tuplify(e, True))

        self.raw_unknowns = []
        self.unknowns = []
        self.coeffs = {}

        for a in self.args:
            if a[1] == '':
                self.sumTotal = a[0]
            else:
                #u = "%s_%d" % (a[1], a[2])
                u = (a[1], a[2])
                # look for all the a**3, b**2 etc
                if u not in self.unknowns:
                    self.unknowns.append(u)
                    # collate coeffs
                    self.coeffs[u] = a[0]
                else:
                    # collate coeffs
                    self.coeffs[u] = self.coeffs[u] + a[0]

                # collect all the a, b, etc
                if a[1] not in self.raw_unknowns:
                    self.raw_unknowns.append(a[1])

    def Solve(self):
        #self.result = "no result"
#        self.stringResult = SolveMatrix(self.raw_unknowns, self.unknowns,
#                                        self.coeffs, self.sumTotal)
        self.stringResult = SolveGrind(self.raw_unknowns, self.unknowns,
                                       self.coeffs, self.sumTotal)