editing a class

[jrp370]

im trying to edit this class so it takes a letter grade instead of a number to find the gpa but im at a total loss any ideas?

class Student:

    def __init__(self, name, hours, qpoints):
        self.name = name
        self.hours = float(hours)
        self.qpoints = float(qpoints)

    def getName(self,name):
        #name=input("what is the students name: ")
        return name

    def getHours(self,hours):
        #hours=eval(input("enter the number of hours: "))
    
        return self.hours
    

    def getQPoints(self,qpoints):
        #qpoints=eval(input("enter the number of quality points: "))
        return self.qpoints

    def gpa(self):
        return self.qpoints/self.hours

    def addGrade(self, qpoints, hours):
        grade=self.qpoints/self.hours
        return(grade)

    def addLetterGrade(self,..,...,):


        return(lettergrade)
        
def makeStudent(name, hours, qpoints):
##    name = input("what is the students name: ")
##    hours = eval(input("enter the number of hours: "))
##    qpoints = eval(input("enter the number of quality points: "))
    print("the grade for", name , "is" , qpoints / hours)
    return Student(name, hours, qpoints)