class Recommender(db.Model):
__tablename__ = 'recommenders'
recommender = db.Column(db.PickleType)
user_id = db.Column(db.Integer,
db.ForeignKey('users.id'),
primary_key=True,
nullable=False)
user = db.relationship('User', back_populates='recommender')
def __repr__(self):
return '<Recommender for user_id={}>'.format(self.user_id)
def fit(self):
features = []
opinions = []
for feedback in self.user.feedback:
features.append(feedback.article.feature)
opinions.append(feedback.opinion)
self.recommender = MultinomialNB().fit(features, opinions)
def recommend(self, k):
features = [article.feature for article in Article.query.all()]
probs = self.recommender.predict_proba(features)
like_idx, = np.where(self.recommender.classes_ == 'like')
like_probs = probs[:, like_idx]
article_ids = np.argpartition(like_probs, range(k))[:k]
return Article.filter(Article.id.in_(article_ids)).all()
class User(db.Model):
__tablename__ = 'users'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(64), index=True, unique=True)
email = db.Column(db.String(128), index=True, unique=True)
password = db.Column(db.String(128))
feedback = db.relationship('Feedback')
recommender = db.relationship('Recommender', back_populates='user')
@property
def is_authenticated(self):
return True
@property
def is_active(self):
return True
@property
def is_anonymous(self):
return False
def get_id(self):
return str(self.id)
def is_recommendable(self):
return len(self.feedback) > 10
def __repr__(self):
return '<User {0!r}>'.format(self.name)
class Category(db.Model):
__tablename__ = 'categories'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(64), nullable=False)
columns = db.relationship('Column', back_populates='category')
def __repr__(self):
return '<Category {0!r}>'.format(self.name)
class Feedback(db.Model):
__tablename__ = 'feedback'
user_id = db.Column(db.Integer,
db.ForeignKey('users.id'),
primary_key=True,
nullable=False)
article_id = db.Column(db.Integer,
db.ForeignKey('articles.id'),
primary_key=True,
nullable=False)
opinion = db.Column(db.String, nullable=False)
article = db.relationship('Article')
class Article(db.Model):
__tablename__ = 'articles'
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String(256), nullable=False)
text = db.Column(db.Text, nullable=False)
feature = db.Column(db.PickleType, nullable=False)
column_id = db.Column(db.Integer,
db.ForeignKey('columns.id'),
nullable=False)
column = db.relationship('Column', back_populates='articles')
def __repr__(self):
return '<Article {0!r}>'.format(self.title)
class Column(db.Model):
__tablename__ = 'columns'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(64), nullable=False)
category_id = db.Column(db.Integer,
db.ForeignKey('categories.id'),
nullable=False)
category = db.relationship('Category', back_populates='columns')
articles = db.relationship('Article', back_populates='column')
def __repr__(self):
return '<Column {0!r}>'.format(self.name)