root / neighbors / neighbours.py

import logging
from model import distance
from model import query
from neartag import NearestByTag
from config import tag_retriever, user_tags_retriever, user_retriever

def get(user, k=10):
    # see how to order by and get only k firts elements
    res = distance.select().execute(user=user).fetchall()
    res = [(el[2], el[1]) for el in res]
    res.sort()
    return res

def compute():
    # tags
    tags = [res[0] for res in query(tag_retriever)]
    users = [res[0] for res in query(user_retriever)]

    # will get the tags, the users, compute
    # the distance, then save them
    solver = NearestByTag(tags)

    for user in users:
        user_tags = [res[0] for res in query(user_tags_retriever % user)]
        solver.add_user(user, user_tags)

    # now gets the computed results, and save them
    distance.delete().execute()

    for user in users:
        neighbours = solver.neighbours(user)
        for value, name in neighbours:
            distance.insert().execute(user=user, neighbour=name,
                                      distance=value)