Python: Calculating GPA with classes using credits and grades

Question

I am so close with this code, I need to figure out to take more than one grade as a parameter. It takes one perfectly but my code is written so it keeps taking grades and credits until nothing is entered. but it doesn't work that way.

My code so far:

#! /usr/bin/python3
# gpa.py
#    Program to take credits and grades and return calculated GPA

class Student:

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

def getName(self):
    return self.name

def getHours(self):
    return self.hours

def getQPoints(self):
    return self.qpoints

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

def addGrade(self, gradePoint, credits):
    self.hours += credits
    self.qpoints += credits*gradePoint

def addLetterGrade(self, grade):
    total = 0
    for i in grade(A,B,C,D,E,F):
        if grade == 'A':
                     total = total + 4.0
        elif grade == 'A-':
                     total = total + 3.7
        elif grade == 'B+':
                     total = total + 3.3
        elif grade == 'B':
                     total = total + 3.0
        elif grade == 'B-':
                     total = total + 2.7
        elif grade == 'C+':
                     total = total + 2.3
        elif grade == 'C':
                     total = total + 2.0
        elif grade == 'C-':
                     total = total + 1.7
        elif grade == 'D+':
                     total = total + 1.3
        elif grade == 'D':
                     total = total + 1.0
        elif grade == 'E':
                     total = total + 0.0
        elif grade == 'F':
                     total = total + 0.0



def main():
    grade = input('Enter grade for next course, or type done finish: ')
    credits = input('Enter number of credit hours for this course: ')
    error_float = 'error: expected a floating-point number'
# make a new Student object
    students = Student('students', 0.0, 0.0)

# user-feedback loop
    while 1:
    # prompt user to enter a grade
        grade_str = input(grade)
    # quit if no grade is entered
        if grade_str.strip() == 'done':
            break

        try:
        # convert input to a floating-point value
            grade = float(grade_str)
        except ValueError:
        # if input cannot be converted, restart feedback loop
            print(error_float)
            continue

    # prompt user to enter the number of credits
        credits_str = input(credits).strip()
        try:
        # convert input to a floating-point value
            credits = float(credits_str)
        except ValueError:
        # if input cannot be converted, restart feedback loop
            print(error_float)
            continue

    # update the student's grades
        students.addGrade(grade, credits)

# after user has entered all grades, compute the cumulative GPA
    if students.getHours() == 0.0:
    # can't compute GPA if hours = 0
        print('*** zero credit hours recorded')
    else:
    # otherwise, output cumulative GPA and finish
        print('*** final GPA =', students.gpa())

if __name__ == '__main__':
    main()

@jeremyD i still need to add the input for credits and there might be more. not sure — user2306249, Apr 22 '13 at 07:31
This is going to be shut down for being too vague. I suggest you ask a specific question and provide a precise directive before that happens. — Mr_Spock, Apr 22 '13 at 08:36
@ConcernedOfTunbridgeWells no just fooling around with programs for one of my classes. — user2306249, Apr 22 '13 at 08:55

score 0 · Answer 1 · answered Apr 22 '13 at 08:54

0

students = Student('students', 0.0, 0.0)

However in the init you got:

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

so you're giving it a string instead of int/float... and you try to convert it to float, which fails

students = Student(0.0, 0.0, 0)

or put name or something in the init:

def __init__(self, name, hours, qpoints, credits):

answered Apr 22 '13 at 08:54

Jrc

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Still returns an error: line 63, in main students = Student(0.0, 0.0, 0) TypeError: __init__() missing 1 required positional argument: 'credits' – user2306249 Apr 22 '13 at 09:01
You need to pass as many args as you define - so for your original example its: hours, qpoints, credits - which is 3. You can ignore the self for now. If you define more args you need to pass more of them. Did you modify the init? – Jrc Apr 22 '13 at 09:10
yes it works but I need to figure out how to take more than one grade as a parameter. It works for one grade for some reason my code isn't continuing until no grade is entered – user2306249 Apr 22 '13 at 09:16
you might want to take a look at this [link](http://stackoverflow.com/questions/141545/overloading-init-in-python/141777#141777) you can simply hand over a list of values – Jrc Apr 22 '13 at 10:07

score 0 · Answer 2 · answered Oct 12 '16 at 20:47

You may try this way...

#! /usr/bin/python3
# gpa.py
#    Program to take credits and grades and return calculated GPA

class Student:
    def __init__(self, hours, qpoints, credits):
        self.hours = float(hours)
        self.qpoints = float(qpoints)

    def getName(self):
        return self.name

    def getHours(self):
        return self.hours

    def getQPoints(self):
        return self.qpoints

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

    def addGrade(self, gradePoint, credits):
        self.hours += credits
        self.qpoints += credits*gradePoint

    def addLetterGrade(self, grade):
        total = 0
        for i in grade(A,B,C,D,E,F):
            if grade == 'A':
                total = total + 4.0
            elif grade == 'A-':
                total = total + 3.7
            elif grade == 'B+':
                total = total + 3.3
            elif grade == 'B':
                total = total + 3.0
            elif grade == 'B-':
                total = total + 2.7
            elif grade == 'C+':
                total = total + 2.3
            elif grade == 'C':
                total = total + 2.0
            elif grade == 'C-':
                total = total + 1.7
            elif grade == 'D+':
                total = total + 1.3
            elif grade == 'D':
                total = total + 1.0
            elif grade == 'E':
                total = total + 0.0
            elif grade == 'F':
                total = total + 0.0



def main():
    grade = input('Enter grade for next course, or type done finish: ')
    credits = input('Enter number of credit hours for this course: ')
    error_float = 'error: expected a floating-point number'
# make a new Student object
#     students = Student('students', 0.0, 0.0) # This is wrong declaration because you initialised "def __init__(self, hours, qpoints, credits): "
    students = Student(0.0, 0.0, 0.0)

# user-feedback loop
    while 1:
    # prompt user to enter a grade
        grade_str = input(grade)
    # quit if no grade is entered
        if grade_str.strip() == 'done':
            break

        try:
        # convert input to a floating-point value
            grade = float(grade_str)
        except ValueError:
        # if input cannot be converted, restart feedback loop
            print(error_float)
            continue

    # prompt user to enter the number of credits
        credits_str = input(credits).strip()
        try:
        # convert input to a floating-point value
            credits = float(credits_str)
        except ValueError:
        # if input cannot be converted, restart feedback loop
            print(error_float)
            continue

    # update the student's grades
        students.addGrade(grade, credits)

# after user has entered all grades, compute the cumulative GPA
    if students.getHours() == 0.0:
    # can't compute GPA if hours = 0
        print('*** zero credit hours recorded')
    else:
    # otherwise, output cumulative GPA and finish
        print('*** final GPA =', students.gpa())

if __name__ == '__main__':
    main()

Python: Calculating GPA with classes using credits and grades

2 Answers2