Python wrapper to store an lp file as a model object

Lp_wrapper

""""
Try to create model, variable and constraint objects.

Try to read the lp into a model object faster.
"""
import os

from profilehooks import profile, timecall

class Model(object):

    def __init__(self):
        self.name = ''
        self.variables = []
        self.constraints = []
        self.obj = ''
        self.sense = 'Maximize'
        self.model_file

    @staticmethod
    def try_split(line):
        if len(line.split(">=")) > 1:
            return (line.split(">="), ">=")
        elif len(line.split("<=")) > 1:
            return (line.split("<="), "<=")
        elif len(line.split("=")) > 1:
            return (line.split("="), "=")
        elif len(line.split(">")) > 1:
            return (line.split(">"), ">")
        elif len(line.split("<")) > 1:
            return (line.split("<"), "<")
                 
    @profile
    def read(self, model_file):
        
        variables = []
        var_names = set()
        constraints = []
        objective = ''
        senses = ['=', '>=', '<=', '>', '<']

        ## Please Refactor ##
        with open(model_file, 'r') as data:
            
            # store current constraint
            tmp = ''

            # when passing through the lp we start
            # in the objective function. Process the
            # objective function and constraints 
            # differently.
            in_constraints = False
            in_variables = False

            title = data.readline()
            make_new_con_next_line = False
            
            # Go through the lp file line by line and
            # create constraint and variable objects.
            for a,line in enumerate(data):
                if a % 100000 == 0:
                    print a
                # The portion of the lp beneath "Subject To"
                if in_constraints:
                    # We're in the variable bounds section
                    if 'Bounds' in line:
                        in_constraints = False
                        in_variables = True
                        continue

                    if ':' in line:
                        if tmp:
                            constraints.append(tmp)
                            tmp = ""
                        split_line = line.split(":")
                        tmp = Constraint(split_line[0])
                        line = split_line[1]
                    elif [bit for bit in line if bit in senses]:
                        split_line, sense = self.try_split(line)
                        tmp.rhs = split_line[1]
                        tmp.sense = sense
                        line = split_line[0]
                    
                    split_at_spaces = line.split(" ")
                    sense = False
                    var = ''
                    coeff_and_sense = ''
                    for item in split_at_spaces:
                        if item == '+' or item == '-':
                            coeff_and_sense = item
                        elif any(i.isalpha() for i in item):
                            var = Variable(item)
                            if var.name not in var_names:
                                variables.append(var)
                                var_names.add(var.name)
                            # If a coefficient is 1 then nothing
                            # is written in the lp file to represent it.
                            # This is the default coefficient.
                            tmp.variables[var.name] = coeff_and_sense

                        elif item.strip():
                            coeff_and_sense += " " + item
                # for now assume all variables are free.
                # If I find a situation where this is not the
                # case then make appropriate changes.
                elif in_variables:
                    if 'free' in line:
                        continue

                # The portion of the lp before "Subect To"
                # This feels unclean, but it's easier than 
                # making a function right now.
                else:
                    if 'ubject' in line:
                        in_constraints = True
                        if tmp:
                            constraints.append(tmp)
                            tmp = ''
                        if ':' in line:
                            tmp = Constraint(line.split(" ")[2][:-1])
                            continue

                    elif 'aximize' in line or 'inimize' in line:
                        make_new_con_next_line = True
                        self.sense = line
                        if ':' in line:
                            tmp = Constraint(line.split(" ")[1][:-1])

                    elif make_new_con_next_line:
                        split_line = line.split(":")
                        tmp = Constraint(split_line[0])
                        tmp.obj = True
                        make_new_con_next_line = False
                        line = split_line[1]

                    if tmp:
                        split_at_spaces = line.split(" ")
                        sense = '+'
                        var = ''
                        coeff_and_sense = ''
                        for item in split_at_spaces:
                            if item == '+' or item == '-':
                                coeff_and_sense = item
                            elif any(i.isalpha() for i in item):
                                var = Variable(item.strip())
                                
                                if var.name not in var_names:
                                    variables.append(var)
                                    var_names.add(var.name)
                                # If a coefficient is 1 then nothing
                                # is written in the lp file to represent it.
                                # This is the default coefficient.
                                tmp.variables[var.name] = coeff_and_sense

                            elif item.strip():
                                coeff_and_sense += " " + item
                                var.obj = float(item)
 
            self.variables = variables
            self.constraints = constraints


class Constraint(object):

    def __init__(self, name):
        self.name = name
        self.variables = {}
        self.rhs = ''
        self.obj = False
        self.obj = 0 # update this to include in the objective function

class Variable(object):

    def __init__(self, name):
        self.name = name
        self.X = ''
        self.UB = float("inf")
        self.LB = 0
        self.obj = 0