fix: NA county_code is valid, not Nan

refs: symerio#73

.vscode/settings.json

@@ -0,0 +1,7 @@
+{
+    "python.testing.pytestArgs": [
+        "."
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true
+}

pgeocode.py

@@ -141,6 +141,27 @@
     "ZA",
 ]
 
+NA_VALUES = [
+    "",
+    "#N/A",
+    "#N/A N/A",
+    "#NA",
+    "-1.#IND",
+    "-1.#QNAN",
+    "-NaN",
+    "-nan",
+    "1.#IND",
+    "1.#QNAN",
+    "<NA>",
+    "N/A",
+    # "NA", # NA is a valid county code for Naples, Italy
+    "NULL",
+    "NaN",
+    "n/a",
+    "nan",
+    "null",
+]
+
 
 @contextlib.contextmanager
 def _open_extract_url(url: str, country: str) -> Any:
@@ -231,7 +252,12 @@ def _get_data(country: str) -> Tuple[str, pd.DataFrame]:
 
         data_path = os.path.join(STORAGE_DIR, country.upper() + ".txt")
         if os.path.exists(data_path):
-            data = pd.read_csv(data_path, dtype={"postal_code": str})
+            data = pd.read_csv(
+                data_path,
+                dtype={"postal_code": str},
+                na_values=NA_VALUES,
+                keep_default_na=False,
+            )
         else:
             download_urls = [
                 val.format(country=country) for val in DOWNLOAD_URL
@@ -243,10 +269,11 @@ def _get_data(country: str) -> Tuple[str, pd.DataFrame]:
                     header=None,
                     names=DATA_FIELDS,
                     dtype={"postal_code": str},
+                    na_values=NA_VALUES,
+                    keep_default_na=False,
                 )
             os.makedirs(STORAGE_DIR, exist_ok=True)
             data.to_csv(data_path, index=None)
-
         return data_path, data
 
     def _index_postal_codes(self) -> pd.DataFrame:
@@ -255,7 +282,10 @@ def _index_postal_codes(self) -> pd.DataFrame:
 
         if os.path.exists(data_path_unique):
             data_unique = pd.read_csv(
-                data_path_unique, dtype={"postal_code": str}
+                data_path_unique,
+                dtype={"postal_code": str},
+                na_values=NA_VALUES,
+                keep_default_na=False,
             )
         else:
             # group together places with the same postal code

test_pgeocode.py

@@ -278,6 +278,14 @@ def test_query_location_exact():
     assert res["state_name"].unique().tolist() == ["Île-de-France"]
 
 
+def test_location_naples():
+    # https://github.com/symerio/pgeocode/issues/73
+    nomi = Nominatim("it")
+    res = nomi.query_location("Napoli")
+    assert res["county_name"].unique().tolist() == ["Napoli"]
+    assert res["county_code"].unique().tolist() == ["NA"]
+
+
 def test_query_location_fuzzy():
     pytest.importorskip("thefuzz")
     nomi = Nominatim("fr")