def creatingvarriables(self):
    self.a = self.model.addVar(lb=0, vtype=GRB.CONTINUOUS, name="y_")
    self.b = self.model.addVar(lb=0, vtype=GRB.CONTINUOUS, name="q_")
    self.model.update()
def constraint1(self):
    lhs1 = self.model.getVarByName("y_")
    lhs1 = 2
    rhs1 = self.model.getVarByName("q_")
    rhs1 = 3
    self.model.update()
    self.model.addConstr(lhs1, GRB.LESS_EQUAL, rhs1)


def printvalues(self):
    self.model.optimize()
    #self.model.printAttr('')
    print self.a.X
    print self.b.X

newobject = abc()
newobject.creatingvarriables()
newobject.constraint1()
newobject.printvalues()