在处理数学时如何“跳过”空白输入？ （蟒蛇）

Question

我正在使用GPA计算器来熟悉python /编程。当每个班级都有输入时，我可以使用它。但是，我不确定如果没有为学分/年级输入任何内容或将其用作空白，该如何跳过该变量。

我尝试将空白字符串添加到字典并将其设置为None，但是仍然出现错误。

grades = {
    'A+' : 4.00,
    'A' : 4.00,
    'A-' : 3.67,
    'B+' : 3.33,
    'B' : 3.00,
    'B-' : 2.67,
    'C+' : 2.33,
    'C' : 2.0,
    'C-' : 1.67,
    'D+' : 1.33,
    'D' : 1.0,
    'F' : 0.0,
    }

grd_num = []
cred = []

grd_num.append(grades[input('Enter the letter grade for your first class\n')])
cred.append(float(input('Enter the amount of credits that your first class is worth\n')))

grd_num.append(grades[input('Enter the letter grade for your second class\n')])
cred.append(float(input('Enter the amount of credits that your second class is worth\n')))

grd_num.append(grades[input('Enter the letter grade for your third class\n')])
cred.append(float(input('Enter the amount of credits that your third class is worth\n')))

grd_num.append(grades[input('Enter the letter grade for your fourth class\n')])
cred.append(float(input('Enter the amount of credits that your fourth class is worth\n')))

grd_num.append(grades[input('Enter the letter grade for your fith class\n')])
cred.append(float(input('Enter the amount of credits that your fith class is worth\n')))

grd_num.append(grades[input('Enter the letter grade for your sixth class\n')])
cred.append(float(input('Enter the amount of credits that your sixth class is worth\n')))

grd_num.append(grades[input('Enter the letter grade for your seventh class\n')])
cred.append(float(input('Enter the amount of credits that your seventh class is worth\n')))

grd_num.append(grades[input('Enter the letter grade for your eighth class\n')])
cred.append(float(input('Enter the amount of credits that your eighth class is worth\n')))


totGPA = ((grd_num[0] * cred[0]) + (grd_num[1] * cred[1]) + (grd_num[2] * cred[2]) + (grd_num[3] * cred[3]) + (grd_num[4] * cred[4]) + (grd_num[5] * cred[5]) + (grd_num[6] * cred[6]) + (grd_num[7] * cred[7]))/sum(cred)

print(totGPA)

我希望用户能够输入从1到8个任意数量的班级。现在，用户只能输入8个班级而不会出错。

Answer 1

这是我可以想到的解决方法。您可以检查用户输入是否为空，并相应地中断输入序列。

$row2

通过检查用户输入是否为空，可以有效地停止提示输入，并用零填充剩余数据。