如何用 Python 制作成绩计算器答案

【问题标题】：How to make a grade calculator in Python如何用 Python 制作成绩计算器
【发布时间】：2019-05-11 13:45:02
【问题描述】：

我是 python 的初学者，我正在处理这个项目，该项目将打印学生的结果。除了百分比之外，我几乎完成了所有事情。看，在我的代码中，程序只会打印百分比最后一个人的分数。我需要让它单独计算每个人的百分比，然后在最后打印出来。非常感谢您的帮助。谢谢

T_marks = 1100
data = {}
while True:
    ask = input("What do you want? ")
    if ask == "y":
        name = input("Enter your name: ")
        marks = int(input("Enter marks: "))
        data[name] = marks
        percentage =(marks / T_marks) * 100
    elif ask == "print":
        for (key,value) in data.items():
            print(key,"::",value)
            if percentage > 90:
                print("Passed with A grade")
            elif percentage >= 70 and percentage < 90:
                print("Passed with B grade")
            elif percentage >= 60 and percentage < 70:
                print("Passed with C grade")
            elif percentage >= 50 and percentage < 60:
                print("passed with D Grade")
            else:
                print("You failed")
    else:
        print("Your work has ended")
        break

【问题讨论】：

我注意到for (key,value) in data.items(): 行之后没有任何缩进，这意味着循环没有主体 - 因此，循环将运行直到它到达最后一项，然后控制在下一行继续。我假设key 和value 变量包含发生这种情况后列表中最后一项的数据。那么，你能修复你的缩进，看看问题是否仍然存在吗？
刚刚修复了缩进...问题仍然存在。
请注意，elif 条件仅在前一个条件为假时才被评估。所以如果你有一个if percentage >= 90，那么elif percentage >= 70 and percentage < 90 上的第二个条件将永远为真

标签： python python-3.x dictionary for-loop while-loop

【解决方案1】：

input() 方法读取一个字符串，但不能转换 e。 G。 "4 4 4 5" 到 int。不带参数的方法split() 会在字符串中创建一个单词列表，如下所示：

"4 5 5" -> ["4", "5", "5"]

将您的输入更改为：

marks_string = input("Enter marks: ")
marks = [int(mark) for mark in marks_string.split()]  # convertion to int

并改变百分比的计算：

percentage =(sum(marks) / T_marks) * 100

【讨论】：

【解决方案2】：

您需要在 print 情况下计算 percentage，这应该可以得到您想要的：

T_marks = 1100
data = {}
while True:
    ask = input("What do you want? ")
    if ask == "y":
        name = input("Enter your name: ")
        marks = int(input("Enter marks: "))
        data[name] = marks
    elif ask == "print":
        for (key,value) in data.items():
            # NOTE percentage is under the case when user asks for print
            percentage =(value / T_marks) * 100
            print(key,"::",value)
            if percentage > 90:
                print("Passed with A grade")
            elif percentage >= 70 and percentage < 90:
                print("Passed with B grade")
            elif percentage >= 60 and percentage < 70:
                print("Passed with C grade")
            elif percentage >= 50 and percentage < 60:
                print("passed with D Grade")
            else:
                print("You failed")
    else:
        print("Your work has ended")
        break

还有两个提示：如果某人的成绩为 90，则此代码将输出 "You failed"。对于其中一种情况，您需要将相等设置为 90。 python还简化了不需要and的比较。这是一个简化版本，并针对 90 的情况进行了修正以获得 A 级：

T_marks = 1100
data = {}
while True:
    ask = input("What do you want? ")
    if ask == "y":
        name = input("Enter your name: ")
        marks = int(input("Enter marks: "))
        data[name] = marks
    elif ask == "print":
        for (key,value) in data.items():
            percentage =(value / T_marks) * 100
            print(key,"::",value)
            if percentage >= 90:
                print("Passed with A grade")
            elif 90 > percentage >= 70:
                print("Passed with B grade")
            elif 70 > percentage >= 60:
                print("Passed with C grade")
            elif 60 > percentage >= 50:
                print("passed with D Grade")
            else:
                print("You failed")
    else:
        print("Your work has ended")
        break

【讨论】：

【解决方案3】：

缩进，在编辑中固定：

T_marks = 1100
data = {}
while True:
    ask = input("What do you want? ")
    if ask == "y":
        name = input("Enter your name: ")
        marks = int(input("Enter marks: "))
        data[name] = marks
        percentage =(marks / T_marks) * 100
    elif ask == "print":
        for (key,value) in data.items():
            print(key,"::",value)
            if percentage > 90:
                print("Passed with A grade")
            elif percentage >= 70 and percentage < 90:
                print("Passed with B grade")
            elif percentage >= 60 and percentage < 70:
                print("Passed with C grade")
            elif percentage >= 50 and percentage < 60:
                print("passed with D Grade")
            else:
                print("You failed")
    else:
        print("Your work has ended")
        break

>>> What do you want? y
>>>Enter your name: Alex
>>>Enter marks: 12
>>>What do you want? y
>>>Enter your name: Michael
>>>Enter marks: 22
>>>What do you want? print
>>>Alex :: 12
>>>You failed
>>>Michael :: 22
>>>You failed
>>>What do you want?

【讨论】：