创建 Scantron 以在 Python 中对测试评分

Question

我的任务是创建一个程序来模拟扫描仪从关闭状态打开，一旦打开它就会比较两个阵列并根据两个阵列的比较显示学生的成绩。我还负责创建类。

我可以打开机器，但分级部分是我遇到问题的地方。我的程序告诉我 'correct is not defined' 在 'grade = Answers (correct, student, theGrade)' 中。我不认为我返回或没有正确传递变量。下面是代码。任何人都可以帮忙吗？？

#this program creates a scantron grading system
#the machine will be turned on, scan the correct answers,
#then will grade the student's answers, and display results

#start class initializing machine off and then switching on
class quizGrader:

 #initialize state of machine off
 def __init__(self):

     self.power = 'Off'

 #create module to ask if the user would like to turn on the machine
 def switch(self):

     #ask user if they'd like to turn on the machine
     powerOn = input('Would you like to turn the machine on? (enter Y for yes)')

     #create if statement for system to be turned on or off
     if powerOn == 'y' or powerOn == 'Y':
         self.power = 'On'

     else:
         self.power = 'Off'

 def get_power(self):
     return self.power

#create class for correct answers, student answers, and
#for the student's scantron to be graded
class Answers:

 #initialize the grades
 def __init__(self, correct, student, theGrade):

     #declare what each self. will be equal to
     self.__correctAnswers = correct
     self.__studentAnswers = student
     self.__studentGrade = theGrade

 #create set method for correctAnswers
 def set_correctAnswers(self, correct):
     self.__correctAnswers = correct
     correct = ['A','B','C','D','E','E','D','C','B','A', \
               'A','B','C','D','E','E','D','C','B','A']
     print('Correct answers have been recorded...')

     return correct
 #create set method for studentAnswers
 def set_studentAnswers(self, student):
     self.__studentAnswers = student
     student = ['B','B','C','D','A','E','D','C','B','A', \
               'A','B','C','D','E','E','D','C','B','A']

     return student
 #create set method for student's scantron to be graded
 def set_studentGrade(self, theGrade):
     self.__studentGrade = theGrade

     right = 0
     index = 1

     #create a for loop and if statement for the right answers
     #to be counted and then calculate the % of the grade
     for index in range(0,20):
        if self.__correctAnswers [index] == self.__studentAnswers [index]:
            right += 1
            percent = float(right/20)
            percent = theGrade

     return theGrade

 #return all the methods previously created
 def get_correctAnswers(self, correct):
    return self.__correctAnswers

 def get_studentAnswers(self, student):
    return self.__studentAnswers

 def get_studentGrade(self, theGrade):
    return self.__studentGrade

#start main module
def main():

 #create an object from the quizGrader class
 machine = quizGrader()

 #display that the machine is off
 print('The machine is powered:', machine.get_power())

 #ask the user if they'd like to turn the machine on
 machine.switch()

 #display the user's choice to turn on or leave machine powered off
 print('The machine is now/still powered:',machine.get_power())

 #create an object from the Answers class
 grade = Answers(correct, student, theGrade)


 #display that the correct answers have been recorded and display the answers
 print('Correct answers have been recorded:',grade.get_correctAnswers())
 print()
 print()
 #display that the student's answers have been recorded and display the answers
 print('Student answers have been recorded:', grade.get_studentAnswers())
 print()

 #grade the student's answers
 grade.studentGrade()

 #display the amount of answers student answered correctly
 #and the percentage of their grade based on correct answers
 print('The student grade is',right,'out of 20 or',percent,'%.')

#close main function    
main()

Answer 1

您的 main 函数中未定义变量 correct。

例如，您可以简单地在行 grade = Answers(correct, student, theGrade) 之前添加行 correct = 'C' 以表明正确答案是 C.

成品看起来像这样：

...
correct = 'C'
grade=Answers(correct, student, theGrade)
...

Answer 2

您还没有定义 correct 或 student 甚至 theGrade 是什么

grade = Answers(correct, student, theGrade)

您需要实例化您创建的类，但实际上您需要在 main() 函数中提供这些变量。

例如：

def main():

 #create an object from the quizGrader class
 machine = quizGrader()

 correct = ['A','B','C','D','E','E','D','C','B','A', \
               'A','B','C','D','E','E','D','C','B','A']

 student = ['B','B','C','D','A','E','D','C','B','A', \
               'A','B','C','D','E','E','D','C','B','A']

会让你走得更远... 仅仅因为您在上面的类中声明了它们并不意味着它们可用。

创建 Scantron 以在 Python 中对测试评分

Creating a Scantron to grade a test in Python

python

arrays

oop

object

initializer