Question

我必须调试这个程序，而对于我的生活，我无法弄明白。我不明白为什么while循环没有运行，当我进入＆＃39;完成＆＃39;我只是得到一个值错误。

# Constant Definitions
MAX_SCORE = 10
MIN_SCORE = 0

def GetValidInput ( prompt ):
    """
    This function continues to ask the user for valid input until it
    it received. The acceptable inputs are integers between 0 and 10
    (inclusive) and the string "done"
    Preconditions: Prompt is expected to be a string that is printed
    out each time the user is asked for a new input.
    Postconditions: The valid input is returned as a string.
    """
    strScore = input ( prompt )
    while ( not str.isdigit(strScore) and strScore != "done" ) or \ 
          ( str.isdigit(strScore) and \
          ( int(strScore) < MIN_SCORE and int(strScore) > MAX_SCORE ) ): 
        if strScore.isdigit :
            print ( "Please enter a number between %0d and %0d." \
                    % ( MIN_SCORE, MAX_SCORE), end=' ' )
        else:
            print ( "Please enter only whole numbers.", end=' ' )
        strScore = input ( prompt )
    return strScore

# Program Instructions
print ( "Enter the homework scores one at a time. Type 'done' when finished." )
allScores = [ 1 ] 
strScore = GetValidInput ( "Enter HW#" + str(len( allScores )) + " score: " )
while ( strScore != "done" ): 
    allScores.append ( int(strScore) / MAX_SCORE ) 
    strScore = GetValidInput ( "Enter HW#" + str(len( allScores )) + " score: " )
letterGrade = "I"
if ( len( allScores ) >= 1 ):
     pctScore = sum ( allScores ) // ( len ( allScores ) * 100 )
elif ( len( allScores ) < 1 ):
     pctScore = 0  
elif ( pctScore < 60 ):
    letterGrade = "F"
elif ( pctScore < 70 ):
    letterGrade = "D"
elif ( pctScore < 77 ):
    letterGrade = "C"
elif ( pctScore < 80 ):
    letterGrade = "C+"
elif ( pctScore < 87 ):
    letterGrade = "B"
elif ( pctScore < 90 ):
    letterGrade = "B+"
else:
    letterGrade = "A"
 print ( "Your percentage score is %.2f%% and your letter grade for the course is a         %0s." \
        % ( pctScore, letterGrade ) )

#end

起初我没有正确调用isdigit。我以为我修好了但是我猜它还是错的，因为它还没有用。我不知道还有什么可以尝试，我真的卡住了

Answer 1

你可能想在这种条件可能出现的条件下进行思考：

int(strScore) < MIN_SCORE and int(strScore) > MAX_SCORE

Answer 2

首先，您错误地计算了百分比：

pctScore = sum ( allScores ) // ( len ( allScores ) * 100 )

应该是

pctScore = (sum(allScores) // len(allScores)) * 100

其次，这一行：

elif ( pctScore < 60 ):

应该只是if，否则只有在len(allScores)不小于或大于或等于1时才会运行，即从不。

最后，请查看PEP-008并明智地格式化您的代码。

Answer 3

粗略猜测，主要问题是脚本编写为在python 3下运行，请参阅print语句，并在python 2下运行它。

你应该尝试的第一个修复是找到python 3安装，并使用它。如果您不能这样做，请将'input'调用更改为'raw_input'，这将修复值errr问题。

我的while循环中的ValueError，我不知道为什么

3 个答案: