old_contents: from __future__ import unicode_literals
  
  from django.db import models
  
  
  class CrimeType(models.Model):
      crime_type = models.CharField(max_length=15)
  
      def __unicode__(self):
          return self.crime_type
  
  
  class Location(models.Model):
      name = models.CharField(max_length=45)
      latitude = models.FloatField()
      longitude = models.FloatField()
  
      def __unicode__(self):
          return self.name
  
  
  class Crime(models.Model):
      timestamp = models.DateTimeField()
      fir_number = models.CharField(max_length=10)
      location = models.ForeignKey(Location, on_delete=models.PROTECT)
      type = models.ForeignKey(CrimeType, on_delete=models.SET_NULL, null=True)
  
      def __unicode__(self):
          return self.fir_number
  
  
  class Sansad(models.Model):
      first_name = models.CharField(max_length=45)
      last_name = models.CharField(max_length=45)
      gender = models.CharField(max_length=1)
      party = models.CharField(max_length=45)
      no_of_questions = models.PositiveSmallIntegerField()
      attendance = models.PositiveSmallIntegerField()
      mp_id = models.CharField(max_length=45)
      location = models.ForeignKey(Location, on_delete=models.PROTECT)
  
      def __unicode__(self):
          return self.first_name
  
new_contents: from __future__ import unicode_literals
  
  from django.db import models
  
  
  class CrimeType(models.Model):
      crime_type = models.CharField(max_length=45, unique=True)
  
      def __unicode__(self):
          return self.crime_type
  
  
  class Location(models.Model):
      name = models.CharField(max_length=255, unique=True)
      latitude = models.FloatField()
      longitude = models.FloatField()
  
      def __unicode__(self):
          return self.name
  
  
  class Crime(models.Model):
      timestamp = models.DateTimeField()
      fir_number = models.CharField(max_length=10)
      location = models.ForeignKey(Location, on_delete=models.PROTECT)
      type = models.ForeignKey(CrimeType, on_delete=models.SET_NULL, null=True)
  
      def __unicode__(self):
          return self.fir_number
  
  
  class Sansad(models.Model):
      first_name = models.CharField(max_length=45)
      last_name = models.CharField(max_length=45)
      gender = models.CharField(max_length=1)
      party = models.CharField(max_length=45)
      no_of_questions = models.PositiveSmallIntegerField()
      attendance = models.PositiveSmallIntegerField()
      mp_id = models.CharField(max_length=45, unique=True)
      location = models.ForeignKey(Location, on_delete=models.PROTECT)
  
      def __unicode__(self):
          return self.first_name
  
subject: Add minor changes in models.py