Python：使用学分和成绩计算课程的 GPA答案

【问题标题】：Python: Calculating GPA with classes using credits and gradesPython：使用学分和成绩计算课程的 GPA
【发布时间】：2013-04-15 00:32:15
【问题描述】：

我对这段代码非常接近，我需要弄清楚将多个等级作为参数。它需要一个完美的，但我的代码是编写的，所以它会不断地获得成绩和学分，直到没有输入任何内容。但它不是那样工作的。

到目前为止我的代码：

#! /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()

【问题讨论】：

好的，很好。它有什么问题？
@jeremyD 我仍然需要为学分添加输入，可能还有更多。不确定
这会因为太模糊而被关闭。我建议您在此之前提出一个具体问题并提供准确的指示。
@Mr_Spock 已经更新了我的问题
这是一道作业题吗？

标签： python class methods python-3.x

【解决方案1】：

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

但是在 init 中你得到了：

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

所以你给它一个字符串而不是 int/float... 你尝试将它转换为浮点数，失败了

students = Student(0.0, 0.0, 0)

或在init中输入名称或其他内容：

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

【讨论】：

仍然返回错误：第 63 行，主要学生 = Student(0.0, 0.0, 0) TypeError: __init__() missing 1 required positional argument: 'credits'
您需要传递您定义的尽可能多的参数 - 因此对于您的原始示例，它：小时，qpoints，信用 - 是 3。您现在可以忽略自我。如果您定义更多参数，则需要传递更多参数。你修改了init吗？
是的，它有效，但我需要弄清楚如何将多个等级作为参数。由于某种原因，它适用于一个年级，直到没有输入任何年级，我的代码才会继续
你可能想看看这个link你可以简单地交出一个值列表

【解决方案2】：

你可以试试这个方法……

#! /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()

【讨论】：