How to define Auto evaluation and attempted multiple times constraint in MCQ for django model? - python-3.6

Question

I am working on a MCQ based django project and based on my research I have below models that I got from 3rd party reference. Of course I had to make some modification based on my custom need. below is the snippet from models.py:
from django.db import models
from django.contrib.auth.models import User
from django.template.defaultfilters import slugify
from django.db.models.signals import post_save, pre_save
from django.dispatch import receiver
class Quiz(models.Model):
name = models.CharField(max_length=1000)
questions_count = models.IntegerField(default=0)
description = models.CharField(max_length=70)
created = models.DateTimeField(auto_now_add=True,null=True,blank=True)
slug = models.SlugField()
roll_out = models.BooleanField(default=False)
class Meta:
ordering = ['created', ]
verbose_name_plural = 'Quizzes'
def __str__(self):
return self.name
class Question(models.Model):
quiz = models.ForeignKey(Quiz, on_delete=models.CASCADE)
label = models.CharField(max_length=1000)
order = models.IntegerField(default=0)
marks = models.IntegerField(default=0)
optional = models.BooleanField(default=False)
def __str__(self):
return self.label
class Answer(models.Model):
question = models.ForeignKey(Question, on_delete=models.CASCADE)
text = models.CharField(max_length=1000)
is_correct = models.BooleanField(default=False)
def __str__(self):
return self.text
class QuizTakers(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
quiz = models.ForeignKey(Quiz, on_delete=models.CASCADE)
correct_answers = models.IntegerField(default=0)
completed = models.BooleanField(default=False)
timestamp = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.user.username
class Response(models.Model):
quiztaker = models.ForeignKey(QuizTakers, on_delete=models.CASCADE)
question = models.ForeignKey(Question, on_delete=models.CASCADE)
answer = models.ForeignKey(Answer,on_delete=models.CASCADE,null=True,blank=True)
def __str__(self):
return self.question.label
#receiver(post_save, sender=Quiz)
def set_default_quiz(sender, instance, created, **kwargs):
quiz = Quiz.objects.filter(id=instance.id)
quiz.update(questions_count=instance.question_set.filter(quiz=instance.pk).count())
#receiver(post_save, sender=Question)
def set_default(sender, instance, created, **kwargs):
quiz = Quiz.objects.filter(id=instance.quiz.id)
quiz.update(questions_count=instance.quiz.question_set.filter(quiz=instance.quiz.pk).count())
#receiver(pre_save, sender=Quiz)
def slugify_title(sender, instance, *args, **kwargs):
instance.slug = slugify(instance.name)
However, there are couple of points that I have implement for my MCQs for which I am not able to find proper solution. Below are the points.
1) Every quiz can be attempted multiple times by the quiz taker. No restriction.
2) Since the questions are in MCQ format, the quiz taker answers are auto-evaluated by the application.
Any help would be highly appreciated.
Thank you.

Answer 1

To answer both your questions:
Since every quiz can be done multiple times you will simply have a reset button. Once that button is clicked, it will delete the QuizTaker. You will then be able to create it again.
When you create a quiz all the questions have answers and one of those answers is correct. Therefore, you can define a function that checks if the response provided is equal to the correct answer then increment the number of correct answers by 1 for each correct answer.
I hope this helps!!