def __init__(self, db, idb=None, movies=None, k=5, sim_method=sim_cosine,
r_method='uniform', rec_type='ub'):
self.k = k
self.movies = movies
self.sim_method = sim_method
if rec_type == 'ub':
self.db = db # a dictionary for all items.
self.idb = idb
else:
self.db = idb
self.idb = db
self.r_method = r_method
self.adapt = MovieLensAdapter(self.db, self.idb) # adapter
self.parallel = get_p_dist()
