How to use the pysces.lib.lex function in pysces

if self.Debug:
                print(self.tabmodule)
                print(self.debugfile)

            pysces.lib.lex.lex(module=self, debug=self.Debug)
            pysces.lib.lex.input(Model)
            pysces.lib.yacc.yacc(module=self,
                    debug=self.Debug,
                    debugfile=self.debugfile,
                    tabmodule=self.tabmodule)

            os.chdir(outdir)

            while 1:
                tok = pysces.lib.lex.token()
                if not tok: break
            if self.LexErrors != []: print('self.LexErrors = ', self.LexErrors, '\n')

            while 1:
                p = pysces.lib.yacc.parse(Model)
                if not p: break

            # we have the dictionary get rid of this stuff
            del Model, p

            # Create list of variable reagents and remove '[t]' from fixed reagents
            for i in range(len(self.Reagents)):       # johann -- new construction otherwise list elements not replaced
                if self.Reagents[i][:-3] not in self.FixedReagents:
                    self.VarReagents.append(self.Reagents[i])
                if self.Reagents[i][:-3] in self.FixedReagents:
                    self.Reagents[i] = self.Reagents[i][:-3]

FileT = ''
            for let in FileL:
                if let.isalnum():
                    FileT += let
            self.debugfile = '_pys' + FileT[:-3] + ".dbg"
            self.tabmodule = '_pys' + FileT[:-3] + "_" + "parsetab"
        else:
            self.debugfile = '_pys' + modelfile[:-4] + ".dbg"
            self.tabmodule = '_pys' + modelfile[:-4] + "_" + "parsetab"

        if self.display_debug:
            print(self.tabmodule)
            print(self.debugfile)
            print('cwd: ', os.getcwd())

        self.__lexer = pysces.lib.lex.lex(module=self, debug=self.display_debug)
        self.__lexer.input(self.__Model)
        self.__parser = pysces.lib.yacc.yacc(module=self,
                debug=self.display_debug,
                debugfile=self.debugfile,
                tabmodule=self.tabmodule,
                outputdir=tempDir)

        while 1:
            tok = self.__lexer.token()
            if not tok: break

        while 1:
            p = self.__parser.parse(self.__Model)
            if not p: break

        # get to our work directory

debug [default=0]:  optionally output debug information

        """
        if indir == None:
            indir = os.getcwd()
        if outdir == None:
            outdir = os.getcwd()
        if os.path.exists(os.path.join(indir,File)) and File[-4:] == '.psc':
            go = 1
        else:
            print('\nIgnoring non-PySCeS model file: ' + os.path.join(indir,File))
            go = 0

        if go == 1:
            # clean up the modules
            reload(pysces.lib.lex)		# brett's bugbear code these have to be here ALWAYS!!
            reload(pysces.lib.yacc)
            # clean up the instance
            self.ReactionIDs = [] # List of reaction names
            self.Names = []       # List of all reagent, parameter and function names
            self.LexErrors = []   # List of lexing errors
            self.NetworkDict = {}    # Dictionary containing all reaction information
            self.InitStrings = []    # Initialisation strings

            self.Inits = []          # Initialised entities
            self.Reagents = []       # All reagents found during parsing of reactions
            self.FixedReagents = []  # Fixed reagents
            self.ReacParams = []     # Temporary list of reaction parameters
            self.ParseErrors = []

            self.InitParStrings = []    # Initialisation strings for parameters -- johann new
            self.InitVarStrings = []    # Initialisation strings for variables -- johann new

for let in FileL:
                    if let.isalnum():
                        FileT += let

                # instantiate the lexer and parser
                self.debugfile = '_jws' + FileT[:-3] + ".dbg"
                self.tabmodule = '_jws' + FileT[:-3] + "_" + "parsetab"
            else:
                self.debugfile = '_jws' + File[:-4] + ".dbg"
                self.tabmodule = '_jws' + File[:-4] + "_" + "parsetab"

            if self.Debug:
                print(self.tabmodule)
                print(self.debugfile)

            pysces.lib.lex.lex(module=self, debug=self.Debug)
            pysces.lib.lex.input(Model)
            pysces.lib.yacc.yacc(module=self,
                    debug=self.Debug,
                    debugfile=self.debugfile,
                    tabmodule=self.tabmodule)

            os.chdir(outdir)

            while 1:
                tok = pysces.lib.lex.token()
                if not tok: break
            if self.LexErrors != []: print('self.LexErrors = ', self.LexErrors, '\n')

            while 1:
                p = pysces.lib.yacc.parse(Model)
                if not p: break

if let.isalnum():
                        FileT += let

                # instantiate the lexer and parser
                self.debugfile = '_jws' + FileT[:-3] + ".dbg"
                self.tabmodule = '_jws' + FileT[:-3] + "_" + "parsetab"
            else:
                self.debugfile = '_jws' + File[:-4] + ".dbg"
                self.tabmodule = '_jws' + File[:-4] + "_" + "parsetab"

            if self.Debug:
                print(self.tabmodule)
                print(self.debugfile)

            pysces.lib.lex.lex(module=self, debug=self.Debug)
            pysces.lib.lex.input(Model)
            pysces.lib.yacc.yacc(module=self,
                    debug=self.Debug,
                    debugfile=self.debugfile,
                    tabmodule=self.tabmodule)

            os.chdir(outdir)

            while 1:
                tok = pysces.lib.lex.token()
                if not tok: break
            if self.LexErrors != []: print('self.LexErrors = ', self.LexErrors, '\n')

            while 1:
                p = pysces.lib.yacc.parse(Model)
                if not p: break

self.TimeFunc = []
        self.UserFunc = []
        self.InitFunc = []
        self.Functions = {}
        self.Events = {}
        self.AssignmentRules = {}
        self.UserFuncs = {}
        self.ModelInit = {}
        self.cbm_FluxBounds = {}  # flux bounds in a CB model
        self.cbm_ObjectiveFunctions = {} # objective functions for a CB model
        self.cbm_UserFluxConstraints = {} # objective functions for a CB model

        self.ModelUsesNumpyFuncs = False

        # 4 hrs of debugging and these two lines solve the problem .... I'm out of here!
        reload(pysces.lib.lex)
        reload(pysces.lib.yacc)
        # fixes the obscure reload <--> garbage collection reference overload bug ... who said scripted lang's were
        # easy to use :-) - brett 20040122

        self.AllRateEqsGiven = 1
        self.ParseOK = True
        self.LexOK = True

        # check to see if the last line of the file is an os defined empty line
        self.CheckLastLine(os.path.join(modeldir,modelfile))

        # load model data from file
        Data = open(os.path.join(modeldir,modelfile),'r')
        self.__Model = Data.read()
        Data.close()