In this application, we need to store the data related to each movie and the movies' ratings from each user of the website. We set up three models:
class UserProfile(models.Model):
user = models.ForeignKey(User, unique=True)
array = jsonfield.JSONField()
arrayratedmoviesindxs = jsonfield.JSONField()
lastrecs = jsonfield.JSONField()
def __unicode__(self):
return self.user.username
def save(self, *args, **kwargs):
create = kwargs.pop('create', None)
recsvec = kwargs.pop('recsvec', None)
print 'create:',create
if create==True:
super(UserProfile, self).save(*args, **kwargs)
elif recsvec!=None:
self.lastrecs = json.dumps(recsvec.tolist())
super(UserProfile, self).save(*args, **kwargs)
else:
nmovies = MovieData.objects.count()
array = np.zeros(nmovies)
ratedmovies = self.ratedmovies.all()
self.arrayratedmoviesindxs = json.dumps([m.movieindx for m in ratedmovies])
for m in ratedmovies:
array[m.movieindx] = m.value
self.array = json.dumps(array.tolist())
super(UserProfile, self).save(*args, **kwargs)
class MovieRated(models.Model):
user = models.ForeignKey(UserProfile, related_name='ratedmovies')
movie = models.CharField(max_length=100)
movieindx = models.IntegerField(default=-1)
value = models.IntegerField()
class MovieData(models.Model):
title = models.CharField(max_length=100)
array = jsonfield.JSONField()
ndim = models.IntegerField(default=300)
description = models.TextField()The model MovieData stores the data for each movie: title, description, and vector representation (ndim is the dimension of the vector representation). MovieRated records each movie rated by the user logged in (each object MovieRated is associated with has a UserProfile that utilizes the website). The UserProfile model stores all the users that sign up to the website, so they can rate movies and receive recommendations. Each UserProfile extends the default Django user model by adding the array field, which stores all the movie's ratings from the user, and the recsvec field which stores his last recommendations: the save function is overridden to fill the array field with all the MovieRated objects associated with the user (if the else statement is true), and to fill the lastrecs field with the last recommendations (else if statement). Note that the MovieRated model has a UserProfile foreign key with the related_name equal to ratedmovies: in the save function of the UserProfile model, self.ratedmovies.all() refers to all the RatedMovie objects that have the same UserProfile value. The field arrayratedmoviesindxs on the UserProfile model records all the movies rated by the user and it is used by the API of the application.
To write these data structures on the database we need to run:
python manage.py makemigrations python manage.py migrate