common.py

import json

from pymongo import MongoClient

config = json.load(open('.config'))
tmdb_key = config['tmdb_api_key']
client = MongoClient(config['host'], config['port'])
database = client[config['database']]

meta = database[config['collections']['meta']]
users = database[config['collections']['users']]
movies = database[config['collections']['movies']]
user_similarity = database[config['collections']['user_similarity']]
deviations = database[config['collections']['deviations']]

metadata = None
user_age_range = None

def initialize():
    global metadata
    global user_age_range
    metadata = meta.find({}, {'_id': 0, 'zip_codes': 0}).next()
    user_age_range = users.aggregate([{
        '$group': {
            '_id': 0,
            'max': {'$max': '$age'},
            'min': {'$min': '$age'}
        } }]).next()

if len(list(database.list_collections())) != 0:
    initialize()

def normalize(old_value, old_max, old_min, new_max, new_min):
    old_range = (old_max - old_min)
    if old_range == 0:
        new_value = new_min
    else:
        new_range = (new_max - new_min)
        new_value = (((old_value - old_min) * new_range) / float(old_range)) + new_min

    return new_value