Student.py

class Student(object):

    def __init__(self, course):
        """Initialises object 'Student' with a course name.
        """
        self.course = course
        self.subjectList = []

    def addSubject(self, *args):
        """Defines (a) new object(s) from class 'Student'.
        Adds that object to self.subjectList.
        """
        for newSubjectName in args:
            self.subjectList.append(self.Subject(newSubjectName))

    def printStats(self):
        """Prints the names of the subjects in subjectList."""
        for i in range(len(self.subjectList)):
            print("Subject " + str(i+1) + ": " + self.subjectList[i].subjectName)

    def avgMark(self):
        """Loops through all subjects in subjectList.
        Appends the sum of the subject's marks to total.
        Appends the amount of marks in the subject to count.
        Returns the average.
        """
        total = 0
        count = 0

        for subject in self.subjectList:
            total += sum(subject.marks)
            count += len(subject.marks)
        return total / count

    class Subject(object):

        def __init__(self, subjectName):
            self.subjectName = subjectName
            self.marks = []

        def assignMarks(self, *args):
            """Takes marks from *args. Appends them to self.marks.
            Marks must be between 1 and 10. If they're not, an exception will be raised.
            """
            for mark in args:
                if mark >= 1 and mark <= 10:
                    self.marks.append(mark)
                else:
                    raise Exception("Incorrect value for mark")

def main():
    s = Student("Software engineering")
    s.addSubject("Programming", "Analytics", "Maths", "Computer Organisation")
    s.printStats()
    s.subjectList[0].assignMarks(7, 3.8, 10)
    s.subjectList[1].assignMarks(6.7, 5, 6)
    s.subjectList[2].assignMarks(7.3, 1)
    s.subjectList[3].assignMarks(8.5)
    print(s.avgMark())

if __name__ == "__main__":
    main()