Fix NPE in geocache.py, Add save on fail

src/main/geocache.py

@@ -22,29 +22,35 @@ class Geocache:
         if os.path.isfile(self.JSON_FILE):
             with open(self.JSON_FILE, 'r') as rf:
                 self.__geo_cache.update(json.load(rf))
+            print(f'Geocache loaded from {self.JSON_FILE}')
 
     def __save_geo_cache(self) -> None:
         with open(self.JSON_FILE, 'w') as wf:
             json.dump(self.__geo_cache, wf)
-        print('Geocache saved')
+        print(f'Geocache saved to {self.JSON_FILE}')
 
     def update_geo_cache(self, cities: List[str]) -> None:
         is_changed: bool = False
-        for city in cities:
-            if Utils.is_empty_str(city):
-                continue
-            result: () = self.__geo_cache.get(city)
-            if result is not None:
-                continue
-            print(f'{len(self.__geo_cache.keys())}/{len(cities)} - Try to load geocode for {city}')
-            location: Point = self.__geocode(city)
-            result: () = (location.latitude, location.longitude)
-            self.__geo_cache[city] = result
-            is_changed = True
-            if len(self.__geo_cache.keys()) % 50 == 0:
+        try:
+            for city in cities:
+                if Utils.is_empty_str(city):
+                    continue
+                result: () = self.__geo_cache.get(city)
+                if result is not None:
+                    continue
+                print(f'{len(self.__geo_cache.keys())} - Try to load geocode for {city}')
+                location: Point = self.__geocode(city)
+                if location is None:
+                    self.__geo_cache[city] = ''
+                else:
+                    result: [] = [location.latitude, location.longitude]
+                    self.__geo_cache[city] = result
+                is_changed = True
+                if len(self.__geo_cache.keys()) % 50 == 0:
+                    self.__save_geo_cache()
+        finally:
+            if is_changed:
                 self.__save_geo_cache()
-        if is_changed:
-            self.__save_geo_cache()
 
     def get_location(self, city: str) -> ():
         return self.__geo_cache.get(city)