def index():
if request.method == 'POST':
rating = request.form['rating']
recipe_id = request.form['recipe']
error = None
if error is not None:
flash(error)
else:
db = get_db()
db.execute(
'INSERT INTO rating (recipe_id, user_id, rating)'
' VALUES (?, ?, ?)', (recipe_id, g.user['id'], rating))
db.commit()
return redirect('/')
else:
db = get_db()
recipe = db.execute(
'SELECT * FROM recipe r WHERE r.id'
' NOT IN (SELECT recipe_id FROM rating WHERE user_id = ?)'
' ORDER BY RANDOM() LIMIT 1', (g.user['id'], )).fetchone()
recommendations = recommender.getRecommendations(g.user['id'])
recommendation_ids = [x[1] for x in recommendations]
recommendation_ids_sql = tuple(recommendation_ids)
recommended_recipes = db.execute(
'SELECT * FROM recipe WHERE id IN {}'.format(
recommendation_ids_sql))
return render_template('rating/index.html',
recipe=recipe,
recommendations=recommended_recipes)
def register():
if request.method == 'POST':
email = request.form['email']
password = request.form['password']
db = get_db()
error = None
if not email:
error = 'Email is required.'
elif not password:
error = 'Password is required.'
elif db.execute(
'SELECT id FROM user WHERE email = ?', (email,)
).fetchone() is not None:
error = 'User {} is already registered.'.format(email)
if error is None:
db.execute(
'INSERT INTO user (email, password) VALUES (?, ?)',
(email, generate_password_hash(password))
)
db.commit()
return redirect(url_for('auth.login'))
flash(error)
return render_template('auth/register.html')
def getRecommendations(person, similarity=sim_pearson):
db = get_db()
person = str(person)
users = db.execute('SELECT id FROM user').fetchall()
user_list = [str(x[0]) for x in users]
reviews = dict(
db.execute('SELECT recipe_id, rating FROM rating WHERE user_id = ?',
person).fetchall())
totals = {}
simSums = {}
for other in user_list:
if other == person: continue
sim = similarity(person, other)
if sim <= 0: continue
other_reviews = dict(
db.execute(
'SELECT recipe_id, rating FROM rating WHERE user_id = ?',
other).fetchall())
for item in other_reviews:
if item not in reviews or reviews[item] == 0:
totals.setdefault(item, 0)
totals[item] += other_reviews[item] * sim
simSums.setdefault(item, 0)
simSums[item] += sim
rankings = [(total / simSums[item], item)
for item, total in totals.items()]
rankings.sort()
rankings.reverse()
return rankings
def load_logged_in_user():
user_id = session.get('user_id')
if user_id is None:
g.user = None
else:
g.user = get_db().execute(
'SELECT * FROM user WHERE id = ?', (user_id,)
).fetchone()
def topMatches(person, n=5, similarity=sim_pearson):
db = get_db()
users = db.execute('SELECT id FROM user').fetchall()
user_list = [str(x[0]) for x in users]
scores = [(similarity(person, other), other) for other in user_list
if other != person]
scores.sort()
scores.reverse()
return scores[0:n]
def sim_distance(p1, p2):
db = get_db()
p1reviews = dict(
db.execute('SELECT recipe_id, rating FROM rating WHERE user_id = ?',
p1).fetchall())
p2reviews = dict(
db.execute('SELECT recipe_id, rating FROM rating WHERE user_id = ?',
p2).fetchall())
si = {}
for item in p1reviews:
if item in p2reviews:
si[item] = 1
if len(si) == 0: return 0
sum_of_squares = sum(
[pow(p1reviews[item] - p2reviews[item], 2) for item in si])
return 1 / (1 + sqrt(sum_of_squares))
def login():
if request.method == 'POST':
email = request.form['email']
password = request.form['password']
db = get_db()
error = None
user = db.execute(
'SELECT * FROM user WHERE email = ?', (email,)
).fetchone()
if user is None:
error = 'Incorrect email address.'
elif not check_password_hash(user['password'], password):
error = 'Incorrect password.'
if error is None:
session.clear()
session['user_id'] = user['id']
return redirect(url_for('rating.index'))
flash(error)
return render_template('auth/login.html')
def sim_pearson(p1, p2):
db = get_db()
p1reviews = dict(
db.execute('SELECT recipe_id, rating FROM rating WHERE user_id = ?',
p1).fetchall())
p2reviews = dict(
db.execute('SELECT recipe_id, rating FROM rating WHERE user_id = ?',
p2).fetchall())
si = {}
for item in p1reviews:
if item in p2reviews: si[item] = 1
n = len(si)
if n == 0: return 0
sum1 = sum([p1reviews[it] for it in si])
sum2 = sum([p2reviews[it] for it in si])
sum1Sq = sum([pow(p1reviews[it], 2) for it in si])
sum2Sq = sum([pow(p2reviews[it], 2) for it in si])
pSum = sum([p1reviews[it] * p2reviews[it] for it in si])
num = pSum - (sum1 * sum2 / n)
den = sqrt((sum1Sq - pow(sum1, 2) / n) * (sum2Sq - pow(sum2, 2) / n))
if den == 0: return 0
r = num / den
return r