Question

我使用的是Python 3.4.1，我正在尝试编写执行以下操作的代码：

class Student(object):
    def __init__(self, name):
        self.name, self.grades = name, []

    def append_grade(self, grade):
        self.grades.append(grade)

    def average(self):
        return sum(self.grades) / len(self.grades)

    def letter_grade(self):
        average = self.average()
        for value, grade in (90, "A"), (80, "B"), (70, "C"), (60, "D"):
            if average >= value:
                return grade
        else:
            return "F"

def main():
    print()
    a_class = []  # "class" by itself is a reserved word in Python, avoid using
    while True:
        print()
        print('{} students in class so far'.format(len(a_class)))
        another_student = input('Do you have another student to enter (y/n) ? ')
        if another_student[0].lower() != 'y':
            break
        print()
        student_name = input('What is the student\'s ID? ')
        a_class.append(Student(student_name))
        print()
        print('student :', student_name)
        print('------------------------------------------------')
        number_of_tests = int(input('Please enter the number of tests : '))
        for test_num in range(1, number_of_tests+1):
            print('test grade {}'.format(test_num), end='')
            score = float(input(' : '))
            if score < 0:  # stop early?
                break
        number_of_assignments = int(input('Please enter the number of assignments : '))
        for assignment_num in range(1, number_of_assignments+1):
            print('assignment grade {}'.format(assignment_num), end='')
            score2 = float(input(' : '))
            if score2 < 0:  # stop early?
                break
        number_of_participation = int(input('Please enter 1 to add participation grade : '))
        for participation_num in range(1, number_of_participation+1):
            print('participation grade {}'.format(participation_num), end='')
            score3 = float(input(' : '))
            if score3 < 0:  # stop early?
                break

            a_class[-1].append_grade(score + score2 + score3) # append to last student added

    print_report(a_class)

def print_report(a_class):
    print()
    print('Student Grades')
    print()
    for student in sorted(a_class, key=lambda s: s.name):
        print('student: {:20s} average test score: {:3.2f}  grade: {}'.format(
            student.name, student.average(), student.letter_grade()))
    print()
    print('The class average is {:.2f}'.format(class_average(a_class)))

def class_average(a_class):
    return sum(student.average() for student in a_class) / len(a_class)

main()

这里的任务是通过添加3个不同的东西并获得平均值来获得学生的字母等级。我需要能够输入考试成绩，作业分数和1个参与等级。那些需要平均并给我一个最终的字母等级。我能够找到如何只做一组平均分数但是当我加上其他分数时，平均值是错误的。我可以在这里编辑什么？

Answer 1

我没有详细看，但是这个：

a_class[-1].append_grade(score + score2 + score3)

...让我怀疑你是在一个等级列表中添加一个值，即高于100％。这可能会导致您的平均值过高。

相反，您应该：

a_class[-1].append_grade(score)
a_class[-1].append_grade(score2)
a_class[-1].append_grade(score3)

寻找集体平均值＆amp;测试用字母等级分配

1 个答案: