vectorsearch-cities example: use explicit imports and fix formatting

Author: greenrobot

example/vectorsearch-cities/main.py

@@ -1,52 +1,54 @@
 from cmd import Cmd
-from objectbox import *
+from objectbox import Entity, Float32Vector, HnswIndex, Id, Store, String
 import time
 import csv
 import os
 
+
 @Entity()
 class City:
     id = Id()
     name = String()
-    location = Float32Vector(index=HnswIndex(
-        dimensions=2,
-        distance_type=VectorDistanceType.EUCLIDEAN
-    ))
+    location = Float32Vector(index=HnswIndex(dimensions=2))
+
 
 def list_cities(cities):
     print("{:3s}  {:25s}  {:>9s}  {:>9s}".format("ID", "Name", "Latitude", "Longitude"))
     for city in cities:
         print("{:3d}  {:25s}  {:>9.2f}  {:>9.2f}".format(
-        city.id, city.name, city.location[0], city.location[1]))
+            city.id, city.name, city.location[0], city.location[1]))
+
 
 def list_cities_with_scores(city_score_tuples):
     print("{:3s}  {:25s}  {:>9s}  {:>9s}  {:>5s}".format("ID", "Name", "Latitude", "Longitude", "Score"))
-    for (city,score) in city_score_tuples:
+    for (city, score) in city_score_tuples:
         print("{:3d}  {:25s}  {:>9.2f}  {:>9.2f}  {:>5.2f}".format(
-        city.id, city.name, city.location[0], city.location[1], score))
+            city.id, city.name, city.location[0], city.location[1], score))
+
 
 class VectorSearchCitiesCmd(Cmd):
     prompt = "> "
+
     def __init__(self, *args):
         Cmd.__init__(self, *args)
         dbdir = "cities-db"
         new_db = not os.path.exists(dbdir)
         self._store = Store(directory=dbdir)
         self._box = self._store.box(City)
-        if new_db: 
+        if new_db:
             with open(os.path.join(os.path.dirname(__file__), 'cities.csv')) as f:
-                r = csv.reader(f) 
+                r = csv.reader(f)
                 cities = []
                 for row in r:
                     city = City()
                     city.name = row[0]
-                    city.location = [ row[1], row[2] ]
+                    city.location = [row[1], row[2]]
                     cities.append(city)
                 self._box.put(*cities)
 
     def do_ls(self, name: str = ""):
         """list all cities or starting with <prefix>\nusage: ls [<prefix>]"""
-        qb = self._box.query( City.name.starts_with(name) )
+        qb = self._box.query(City.name.starts_with(name))
         query = qb.build()
         list_cities(query.find())
 
@@ -62,38 +64,38 @@ def do_city_neighbors(self, args: str):
             num = 5
             if len(args) == 2:
                 num = int(args[1])
-            qb = self._box.query( City.name.equals(city) )
+            qb = self._box.query(City.name.equals(city))
             query = qb.build()
             cities = query.find()
             if len(cities) == 1:
                 location = cities[0].location
                 # +1 for the city
                 qb = self._box.query(
-                    City.location.nearest_neighbor(location, num+1) & City.name.not_equals(city)
+                    City.location.nearest_neighbor(location, num + 1) & City.name.not_equals(city)
                 )
                 neighbors = qb.build().find_with_scores()
                 list_cities_with_scores(neighbors)
             else:
                 print(f"no city found named '{city}'")
-        except ValueError: 
+        except ValueError:
             print("usage: city_neighbors <name>[,<num: default 5>]")
-    
+
     def do_neighbors(self, args):
         """find <num> neighbors next to geo-coord <lat> <long>.\nusage: neighbors <num>,<latitude>,<longitude>"""
         try:
             args = args.split(',')
             if len(args) != 3:
                 raise ValueError()
             num = int(args[0])
-            geocoord = [ float(args[1]), float(args[2]) ]
+            geocoord = [float(args[1]), float(args[2])]
             qb = self._box.query(
                 City.location.nearest_neighbor(geocoord, num)
             )
             neighbors = qb.build().find_with_scores()
             list_cities_with_scores(neighbors)
-        except ValueError: 
+        except ValueError:
             print("usage: neighbors <num>,<latitude>,<longitude>")
-    
+
     def do_add(self, args: str):
         """add new location\nusage: add <name>,<lat>,<long>"""
         try:
@@ -105,11 +107,11 @@ def do_add(self, args: str):
             long = float(args[2])
             city = City()
             city.name = name
-            city.location = [lat,long] 
+            city.location = [lat, long]
             self._box.put(city)
-        except ValueError: 
+        except ValueError:
             print("usage: add <name>,<latitude>,<longitude>")
-   
+
     def do_exit(self, _):
         """close the program"""
         raise SystemExit()