Rethinkdb, Python, and Filter - rethinkdb

Question

So here's a fun reduced snippet on some code I'm working on in Python 2.7 with the latest RethinkDB (1.14). My problem is now I need to add another condition, and there's too many possible combinations. Can this be done in a single filter statement?
query = r.table('messages').order_by(r.desc('created'))
if tag is not None and read is not None:
query = query.filter(lambda n: (n['user_id'] == user_id) &
(n['tags'].contains(tag)) &
(n['read'] == read))
elif read is not None:
query = query.filter(lambda n: (n['user_id'] == user_id) &
(n['read'] == read))
elif tag is not None:
query = query.filter(lambda n: (n['user_id'] == user_id) &
(n['tags'].contains(tag)))
else:
query = query.filter(lambda n: n['user_id'] == user_id)
fields_list = query.skip(skip)\
.limit(limit)\
.run(g.db_conn)
As a side note, this would be so much easier if chained filters worked, essentially acting as an and. But it seems for now you can only have one filter per RethinkDB query.
Edit: Not sure what was happening before, but chaining filters does work.

Answer 1

Turns out this actually works!
def _(n):
return (n['user_id'] == user_id) & \
(n['tags'].contains(tag) if tag is not None else True) & \
(n['read'] == read if read is not None else True)
query = r.table('messages') \
.order_by(r.desc('created')) \
.filter(_) \
.skip(skip)\
.limit(limit)
fields_list = query.run(g.db_conn)
Edit: Also possible:
query = r.table('messages') \
.order_by(r.desc('created')) \
.filter(r.row['user_id'] == user_id) \
.filter(r.row['tags'].contains(tag) if tag is not None else True) \
.filter(r.row['read'] == read if read is not None else True) \
.skip(skip) \
.limit(limit)
fields_list = query.run(g.db_conn)