Better way to find sub strings in Datastore? - python-2.7

Question

I have an aplication where an user inputs a name and the aplication gives back the adress and city for that name
The names are in datastore
class Person(ndb.Model):
name = ndb.StringProperty(repeated=True)
address = ndb.StringProperty(indexed=False)
city = ndb.StringProperty()
There are more than 5 million of Person entities. Names can be formed from 2 to 8 words (yes, there are people with 8 words in his names)
Users can enter any words for the name (in any order) and the aplication will return the first match.("John Doe Smith" is equivalent to " Smith Doe John")
This is a sample of my entities(the way how was put(ndb.put_multi)
id="L12802795",nombre=["Smith","Loyola","Peter","","","","",""], city="Cali",address="Conchuela 471"
id="M19181478",nombre=["Hoffa","Manzano","Linda","Rosse","Claudia","Cindy","Patricia",""], comuna="Lima",address=""
id="L18793849",nombre=["Parker","Martinez","Claudio","George","Paul","","",""], comuna="Santiago",address="Calamar 323 Villa Los Pescadores"
This is the way I get the name from the user:
name = self.request.get('content').strip() #The input is the name (an string with several words)
name=" ".join(name.split()).split() #now the name is a list of single words
In my design, in order to find a way to find and search words in the name for each entity, I did this.
q = Person.query()
if len(name)==1:
names_query =q.filter(Person.name==name[0])
elif len(name)==2:
names_query =q.filter(Person.name==name[0]).filter(Person.name==name[1])
elif len(name)==3:
names_query =q.filter(Person.name==name[0]).filter(Person.name==name[1]).filter(Person.name==name[2])
elif len(name)==4:
names_query =q.filter(Person.name==name[0]).filter(Person.name==name[1]).filter(Person.name==name[2]).filter(Person.name==name[3])
elif len(name)==5:
names_query =q.filter(Person.name==name[0]).filter(Person.name==name[1]).filter(Person.name==name[2]).filter(Person.name==name[3]).filter(Person.name==name[4])
elif len(name)==6:
names_query =q.filter(Person.name==name[0]).filter(Person.name==name[1]).filter(Person.name==name[2]).filter(Person.name==name[3]).filter(Person.name==name[4]).filter(Person.name==name[5])
elif len(name)==7:
names_query =q.filter(Person.name==name[0]).filter(Person.name==name[1]).filter(Person.name==name[2]).filter(Person.name==name[3]).filter(Person.name==name[4]).filter(Person.name==name[5]).filter(Person.name==name[6])
else :
names_query =q.filter(Person.name==name[0]).filter(Person.name==name[1]).filter(Person.name==name[2]).filter(Person.name==name[3]).filter(Person.name==name[4]).filter(Person.name==name[5]).filter(Person.name==name[6]).filter(Person.name==name[7])
Person = names_query.fetch(1)
person_id=Person.key.id()
Question 1
Do you think, there is a better way for searching sub strings in strings (ndb.StringProperty), in my design. (I know it works, but I feel it can be improved)
Question 2
My solution has a problem for entities with repeted words in the name.
If I want to find an entity with words "Smith Smith" it brings me "Paul Smith Wshite" instead of "Paul Smith Smith", I do not know how to modify my query in order to find 2(or more) repeated words in Person.name

Answer 1

You could generate a list of all possible tokens for each name and use prefix filters to query them:
class Person(ndb.Model):
name = ndb.StringProperty(required=True)
address = ndb.StringProperty(indexed=False)
city = ndb.StringProperty()
def _tokens(self):
"""Returns all possible combinations of name tokens combined.
For example, for input 'john doe smith' we will get:
['john doe smith', 'john smith doe', 'doe john smith', 'doe smith john',
'smith john doe', 'smith doe john']
"""
tokens = [t.lower() for t in self.name.split(' ') if t]
return [' '.join(t) for t in itertools.permutations(tokens)] or None
tokens = ndb.ComputedProperty(_tokens, repeated=True)
#classmethod
def suggest(cls, s):
s = s.lower()
return cls.query(ndb.AND(cls.tokens >= s, cls.tokens <= s + u'\ufffd'))
ndb.put_multi([Person(name='John Doe Smith'), Person(name='Jane Doe Smith'),
Person(name='Paul Smith Wshite'), Person(name='Paul Smith'),
Person(name='Test'), Person(name='Paul Smith Smith')])
assert Person.suggest('j').count() == 2
assert Person.suggest('ja').count() == 1
assert Person.suggest('jo').count() == 1
assert Person.suggest('doe').count() == 2
assert Person.suggest('t').count() == 1
assert Person.suggest('Smith Smith').get().name == 'Paul Smith Smith'
assert Person.suggest('Paul Smith').count() == 3
And make sure to use keys_only queries if you only want keys/ids. This will make things significantly faster and almost free in terms of datastore OPs.