Defined the models for randomized variables

deimos/models.py

@@ -1,5 +1,5 @@
 from django.db import models
-from phobos.models import Course, Question, User, Assignment
+from phobos.models import Course, Question, User, Assignment, VariableInstance
 from django.core.validators import MaxValueValidator, MinValueValidator
 class Student(User):
  """
@@ -111,6 +111,15 @@ class QuestionStudent(models.Model):
  question = models.ForeignKey(Question, on_delete=models.CASCADE)
  num_points = models.FloatField(default=0)
  success = models.BooleanField(default=False)
+ # Will probably never use that related name.
+ var_instances = models.ManyToManyField(VariableInstance, related_name='question_students')
+ def get_instances(self):
+ """
+ Get variable instances from the variables associated to the question.
+ """
+ for var in self.question.variables:
+ self.var_instances.add(var.get_instance())
+
  def get_num_points(self):
  """
  Calculates adn returns the number of points a student gets from a question

deimos/views.py

@@ -319,16 +319,18 @@ def transform_expression(expr):
  return transformed_expression
 
 def extract_numbers(text):
- # Regular expression pattern to match floats and ints
- pattern = r'[-+]?\d*\.\d+|\d+'
+ """
+ Returns a list of numbers and subscrippted characters in a string.
+ # E.g of a subscriptted char: 'e_1'
+ """
+ # Regular expression pattern to match numbers and subscriptted chars.
+
+ pattern = r'[-+]?\d*\.\d+|\d+|\w+_\w+'
 
  # Find all matches using the pattern
  matches = re.findall(pattern, text)
 
- # Convert matches to floats or ints
- numbers = [str(match) if '.' in match else str(match) for match in matches]
-
- return numbers
+ return matches
 
 def compare_expressions(expression1, expression2):
  """

phobos/models.py

@@ -2,7 +2,7 @@
 from django.contrib.auth.models import User
 #from django.contrib.postgres.fields import ArrayField
 from django.core.validators import MaxValueValidator, MinValueValidator
-
+import random
 class DifficultyChoices(models.TextChoices):
  EASY = 'EASY', 'Easy'
  MEDIUM = 'MEDIUM', 'Medium'
@@ -317,6 +317,42 @@ class MCQImageAnswer(models.Model):
 
  def __str__(self):
  return f"Image answer for {self.quesiton} with url {self.image.url}" 
+class Variable(models.Model):
+ """
+ A `Question` may have variables associated to it. 
+ A variable will have symbol representing it. Will be one character most of the times
+ but some may be subscripted. E.g epislon_zero may be represented like this 'e_0'
+
+ For example, question with pk 12 may have 5 variables associated to it.
+ Those variable will each have maybe 4 instances and each time a student
+ opens a `Question` for the first time, one of the instances of each variable
+ is going to assigned to `QuestionStudent` object which relates the `Question`
+ and the `Student`.
+ """
+ question = models.ForeignKey(Question, on_delete=models.CASCADE, related_name='variables')
+ symbol = models.CharField(max_length=3, blank=False, null=False)
+
+ def __str__(self):
+ return f"Variable `{self.symbol}` for question {self.question}"
+ def create_instances(self, num, lower_bound, upper_bound, is_int=False):
+ """
+ Creates num number of random variable instances.
+ """
+ for i in num:
+ random_float = random.uniform(lower_bound, upper_bound)
+ if is_int:
+ random_float = float(int(random_float))
+ vi = VariableInstance.objects.create(variable=self, value=random_float)
+ vi.save()
+ def get_instance(self):
+ # This is assuming that instances will already be created.
+ return random.choice(self.instances)
+class VariableInstance(models.Model):
+ """
+ Instance of `Variable`
+ """
+ variable = models.ForeignKey(Variable, on_delete=models.CASCADE, related_name='instances')
+ value = models.FloatField(null=False, blank=False)
 
 class VectorAnswer(models.Model):
  # !Important: Deprecated

phobos/views.py

@@ -154,7 +154,7 @@ def create_assignment(request, course_id=None):
 @login_required(login_url='astros:login')
 def create_question(request, assignment_id=None, type_int=None):
  """
- creates a question object.
+ creates a `Question` object.
  Will usually require the assignment id, and sometimes
  not (in case the questions are stand-alone e.g. in the question bank)
  """