def top_friends_task(user_id):
"""
Pulls all friends and all photo tags, combines them
to get `top_friends_score` and saves to the `User.friends` field
"""
# Run the child tasks
friends_task = run_fql.s(task_cls=GetFriendsTask, user_id=user_id)
tagged_with_me_task = run_fql.s(task_cls=TaggedWithMeTask, user_id=user_id)
job_async = group([friends_task, tagged_with_me_task]).apply_async()
results = job_async.get()
results = merge_dicts(*results)
all_friends = results['get_friends']
tagged_with_me = results['tagged_with_me']
# Collapse the tags by user_id, discount by age
tag_score_by_user_id = defaultdict(lambda: 0.0)
for tag in tagged_with_me.fields:
tag_age = datetime.date.today().year - tag['created'].year + 1.0
tag_score_by_user_id[tag['subject']] += 1 / tag_age
# Sort
user_ids_in_score_order = sorted(tag_score_by_user_id.items(), key=lambda x: x[1])
# Reversing them means the index corresponds to top friends order
top_friends_order_by_id = {}
for top_friends_order, u in enumerate(user_ids_in_score_order):
top_friends_order_by_id[u[0]] = top_friends_order + 1 # 0 is not a valid value
# Copy `top_friends_order`s to `all_friends`
for id, top_friends_order in top_friends_order_by_id.items():
try:
all_friends.fields_by_id[id]['top_friends_order'] = top_friends_order
except KeyError:
# Means you were tagged with someone you aren't friends with
pass
# Save
user = User.objects.get(id=user_id)
# Clear current friends
FacebookFriend.objects(user=user).delete()
# Bulk insert the new ones
docs = []
for friend in results['get_friends'].fields:
uid = friend.pop('id')
docs.append(FacebookFriend(uid=uid, user=user, **friend))
FacebookFriend.objects.insert(docs)
logger.info('Pulled %d friends, %d top friends for user %s'
% (len(all_friends), len(top_friends_order_by_id), user.get_id_str()))
return results
def join_on_field(self, other_getter, map_fxn=None, new_field_name=None,
join_field='id', join_field_1=None, join_field_2=None, discard_orphans=True):
"""
Joins this getter to another by indexing on a field
and applying a mapping function to generate new outputs
discard_orphans : do we discard elements in one that
don't match the other?
"""
if join_field != 'id' or join_field_1 or join_field_2:
join_field_1 = join_field_1 or join_field
join_field_2 = join_field_2 or join_field
getter_by_join_field = {element[join_field_1]: element for element in self.fields}
other_by_join_field = {element[join_field_2]: element for element in other_getter.fields}
else:
getter_by_join_field = self._fields_by_id
other_by_join_field = other_getter._fields_by_id
keys_in_both = set(getter_by_join_field) & set(other_by_join_field)
# Run the mapping function
if map_fxn:
joined = [{
new_field_name: map_fxn(getter_by_join_field[key], other_by_join_field[key]),
# join field is same in both, by definition
join_field: getter_by_join_field[key][join_field]
} for key in keys_in_both]
# If no mapping function, just take all existing fields
else:
joined = [merge_dicts(getter_by_join_field[key], other_by_join_field[key])
for key in keys_in_both]
if not discard_orphans:
# Append the orphans
# Note that this may cause problems if the
# mapping function introduced any new fields
[joined.append(getter_by_join_field[key])
for key in set(getter_by_join_field) - keys_in_both]
[joined.append(other_by_join_field[key])
for key in set(other_by_join_field) - keys_in_both]
# Return a new getter
return self.from_fields(joined)
