calculate average marks in Python

test10.py

class average:
    def total_marks(self):
        self.total_marks_num = input("Enter Total Of Marks : ")
        print "=========================================\n"
    #-------------------------------------------------------------------
    def set_list_of_marks(self):
        mark=0;self.marksList=[];counter=0
        while counter<self.total_marks_num:
            mark=input("Enter Mark #"+str(counter+1)+": ")
            self.marksList.append(float(mark))
            counter+=1
        return self.marksList
    # -------------------------------------------------------------------
    def make_marksAvrege(self):
        average=0;counter=0
        while counter<len(self.marksList):
            average+=float(self.marksList[counter])
            counter+=1
        print "\n\n========================================="
        print "Your Marks Avrage Is : "+str(float(average)/float(len(self.marksList)))

        #or Sum(marklist)/len(self.marksList)

#################################################################################
#################################################################################


obj=average()
obj.total_marks()
obj.set_list_of_marks()
obj.make_marksAvrege()