add type annotations for legacy tokenizer

[nominatim.git] / nominatim / tokenizer / legacy_tokenizer.py

diff --git a/nominatim/tokenizer/legacy_tokenizer.py b/nominatim/tokenizer/legacy_tokenizer.py
index 36fd5722441a12e92d24434d5dc1317497dd27bc..848d619116abde7aeca34d78cf3d330db69eab64 100644 (file)
--- a/nominatim/tokenizer/legacy_tokenizer.py
+++ b/nominatim/tokenizer/legacy_tokenizer.py
@@ -7,8 +7,10 @@
 """
 Tokenizer implementing normalisation as used before Nominatim 4.
 """
 """
 Tokenizer implementing normalisation as used before Nominatim 4.
 """

+from typing import Optional, Sequence, List, Tuple, Mapping, Any, Callable, cast, Dict, Set

 from collections import OrderedDict
 import logging
 from collections import OrderedDict
 import logging

+from pathlib import Path

 import re
 import shutil
 from textwrap import dedent
 import re
 import shutil
 from textwrap import dedent


@@ -17,10 +19,12 @@ from icu import Transliterator
 import psycopg2
 import psycopg2.extras
 
 import psycopg2
 import psycopg2.extras
 

-from nominatim.db.connection import connect
+from nominatim.db.connection import connect, Connection
+from nominatim.config import Configuration

 from nominatim.db import properties
 from nominatim.db import utils as db_utils
 from nominatim.db.sql_preprocessor import SQLPreprocessor
 from nominatim.db import properties
 from nominatim.db import utils as db_utils
 from nominatim.db.sql_preprocessor import SQLPreprocessor

+from nominatim.data.place_info import PlaceInfo

 from nominatim.errors import UsageError
 from nominatim.tokenizer.base import AbstractAnalyzer, AbstractTokenizer
 
 from nominatim.errors import UsageError
 from nominatim.tokenizer.base import AbstractAnalyzer, AbstractTokenizer
 


@@ -29,13 +33,13 @@ DBCFG_MAXWORDFREQ = "tokenizer_maxwordfreq"
 
 LOG = logging.getLogger()
 
 
 LOG = logging.getLogger()
 

-def create(dsn, data_dir):
+def create(dsn: str, data_dir: Path) -> 'LegacyTokenizer':

     """ Create a new instance of the tokenizer provided by this module.
     """
     return LegacyTokenizer(dsn, data_dir)
 
 
     """ Create a new instance of the tokenizer provided by this module.
     """
     return LegacyTokenizer(dsn, data_dir)
 
 

-def _install_module(config_module_path, src_dir, module_dir):
+def _install_module(config_module_path: str, src_dir: Path, module_dir: Path) -> str:

     """ Copies the PostgreSQL normalisation module into the project
         directory if necessary. For historical reasons the module is
         saved in the '/module' subdirectory and not with the other tokenizer
     """ Copies the PostgreSQL normalisation module into the project
         directory if necessary. For historical reasons the module is
         saved in the '/module' subdirectory and not with the other tokenizer


@@ -52,7 +56,7 @@ def _install_module(config_module_path, src_dir, module_dir):
     # Compatibility mode for builddir installations.
     if module_dir.exists() and src_dir.samefile(module_dir):
         LOG.info('Running from build directory. Leaving database module as is.')
     # Compatibility mode for builddir installations.
     if module_dir.exists() and src_dir.samefile(module_dir):
         LOG.info('Running from build directory. Leaving database module as is.')

-        return module_dir
+        return str(module_dir)

 
     # In any other case install the module in the project directory.
     if not module_dir.exists():
 
     # In any other case install the module in the project directory.
     if not module_dir.exists():


@@ -64,10 +68,10 @@ def _install_module(config_module_path, src_dir, module_dir):
 
     LOG.info('Database module installed at %s', str(destfile))
 
 
     LOG.info('Database module installed at %s', str(destfile))
 

-    return module_dir
+    return str(module_dir)

 
 
 
 

-def _check_module(module_dir, conn):
+def _check_module(module_dir: str, conn: Connection) -> None:

     """ Try to use the PostgreSQL module to confirm that it is correctly
         installed and accessible from PostgreSQL.
     """
     """ Try to use the PostgreSQL module to confirm that it is correctly
         installed and accessible from PostgreSQL.
     """


@@ -89,13 +93,13 @@ class LegacyTokenizer(AbstractTokenizer):
         calls to the database.
     """
 
         calls to the database.
     """
 

-    def __init__(self, dsn, data_dir):
+    def __init__(self, dsn: str, data_dir: Path) -> None:

         self.dsn = dsn
         self.data_dir = data_dir
         self.dsn = dsn
         self.data_dir = data_dir

-        self.normalization = None
+        self.normalization: Optional[str] = None

 
 
 
 

-    def init_new_db(self, config, init_db=True):
+    def init_new_db(self, config: Configuration, init_db: bool = True) -> None:

         """ Set up a new tokenizer for the database.
 
             This copies all necessary data in the project directory to make
         """ Set up a new tokenizer for the database.
 
             This copies all necessary data in the project directory to make


@@ -119,7 +123,7 @@ class LegacyTokenizer(AbstractTokenizer):
             self._init_db_tables(config)
 
 
             self._init_db_tables(config)
 
 

-    def init_from_project(self, config):
+    def init_from_project(self, config: Configuration) -> None:

         """ Initialise the tokenizer from the project directory.
         """
         with connect(self.dsn) as conn:
         """ Initialise the tokenizer from the project directory.
         """
         with connect(self.dsn) as conn:


@@ -132,7 +136,7 @@ class LegacyTokenizer(AbstractTokenizer):
 
         self._install_php(config, overwrite=False)
 
 
         self._install_php(config, overwrite=False)
 

-    def finalize_import(self, config):
+    def finalize_import(self, config: Configuration) -> None:

         """ Do any required postprocessing to make the tokenizer data ready
             for use.
         """
         """ Do any required postprocessing to make the tokenizer data ready
             for use.
         """


@@ -141,7 +145,7 @@ class LegacyTokenizer(AbstractTokenizer):
             sqlp.run_sql_file(conn, 'tokenizer/legacy_tokenizer_indices.sql')
 
 
             sqlp.run_sql_file(conn, 'tokenizer/legacy_tokenizer_indices.sql')
 
 

-    def update_sql_functions(self, config):
+    def update_sql_functions(self, config: Configuration) -> None:

         """ Reimport the SQL functions for this tokenizer.
         """
         with connect(self.dsn) as conn:
         """ Reimport the SQL functions for this tokenizer.
         """
         with connect(self.dsn) as conn:


@@ -154,7 +158,7 @@ class LegacyTokenizer(AbstractTokenizer):
                               modulepath=modulepath)
 
 
                               modulepath=modulepath)
 
 

-    def check_database(self, _):
+    def check_database(self, _: Configuration) -> Optional[str]:

         """ Check that the tokenizer is set up correctly.
         """
         hint = """\
         """ Check that the tokenizer is set up correctly.
         """
         hint = """\


@@ -181,7 +185,7 @@ class LegacyTokenizer(AbstractTokenizer):
         return None
 
 
         return None
 
 

-    def migrate_database(self, config):
+    def migrate_database(self, config: Configuration) -> None:

         """ Initialise the project directory of an existing database for
             use with this tokenizer.
 
         """ Initialise the project directory of an existing database for
             use with this tokenizer.
 


@@ -198,7 +202,7 @@ class LegacyTokenizer(AbstractTokenizer):
             self._save_config(conn, config)
 
 
             self._save_config(conn, config)
 
 

-    def update_statistics(self):
+    def update_statistics(self) -> None:

         """ Recompute the frequency of full words.
         """
         with connect(self.dsn) as conn:
         """ Recompute the frequency of full words.
         """
         with connect(self.dsn) as conn:


@@ -218,13 +222,13 @@ class LegacyTokenizer(AbstractTokenizer):
             conn.commit()
 
 
             conn.commit()
 
 

-    def update_word_tokens(self):
+    def update_word_tokens(self) -> None:

         """ No house-keeping implemented for the legacy tokenizer.
         """
         LOG.info("No tokenizer clean-up available.")
 
 
         """ No house-keeping implemented for the legacy tokenizer.
         """
         LOG.info("No tokenizer clean-up available.")
 
 

-    def name_analyzer(self):
+    def name_analyzer(self) -> 'LegacyNameAnalyzer':

         """ Create a new analyzer for tokenizing names and queries
             using this tokinzer. Analyzers are context managers and should
             be used accordingly:
         """ Create a new analyzer for tokenizing names and queries
             using this tokinzer. Analyzers are context managers and should
             be used accordingly:


@@ -244,7 +248,7 @@ class LegacyTokenizer(AbstractTokenizer):
         return LegacyNameAnalyzer(self.dsn, normalizer)
 
 
         return LegacyNameAnalyzer(self.dsn, normalizer)
 
 

-    def _install_php(self, config, overwrite=True):
+    def _install_php(self, config: Configuration, overwrite: bool = True) -> None:

         """ Install the php script for the tokenizer.
         """
         php_file = self.data_dir / "tokenizer.php"
         """ Install the php script for the tokenizer.
         """
         php_file = self.data_dir / "tokenizer.php"


@@ -258,7 +262,7 @@ class LegacyTokenizer(AbstractTokenizer):
                 """), encoding='utf-8')
 
 
                 """), encoding='utf-8')
 
 

-    def _init_db_tables(self, config):
+    def _init_db_tables(self, config: Configuration) -> None:

         """ Set up the word table and fill it with pre-computed word
             frequencies.
         """
         """ Set up the word table and fill it with pre-computed word
             frequencies.
         """


@@ -271,10 +275,12 @@ class LegacyTokenizer(AbstractTokenizer):
         db_utils.execute_file(self.dsn, config.lib_dir.data / 'words.sql')
 
 
         db_utils.execute_file(self.dsn, config.lib_dir.data / 'words.sql')
 
 

-    def _save_config(self, conn, config):
+    def _save_config(self, conn: Connection, config: Configuration) -> None:

         """ Save the configuration that needs to remain stable for the given
             database as database properties.
         """
         """ Save the configuration that needs to remain stable for the given
             database as database properties.
         """

+        assert self.normalization is not None
+

         properties.set_property(conn, DBCFG_NORMALIZATION, self.normalization)
         properties.set_property(conn, DBCFG_MAXWORDFREQ, config.MAX_WORD_FREQUENCY)
 
         properties.set_property(conn, DBCFG_NORMALIZATION, self.normalization)
         properties.set_property(conn, DBCFG_MAXWORDFREQ, config.MAX_WORD_FREQUENCY)
 


@@ -287,8 +293,8 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
         normalization.
     """
 
         normalization.
     """
 

-    def __init__(self, dsn, normalizer):
-        self.conn = connect(dsn).connection
+    def __init__(self, dsn: str, normalizer: Any):
+        self.conn: Optional[Connection] = connect(dsn).connection

         self.conn.autocommit = True
         self.normalizer = normalizer
         psycopg2.extras.register_hstore(self.conn)
         self.conn.autocommit = True
         self.normalizer = normalizer
         psycopg2.extras.register_hstore(self.conn)


@@ -296,7 +302,7 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
         self._cache = _TokenCache(self.conn)
 
 
         self._cache = _TokenCache(self.conn)
 
 

-    def close(self):
+    def close(self) -> None:

         """ Free all resources used by the analyzer.
         """
         if self.conn:
         """ Free all resources used by the analyzer.
         """
         if self.conn:


@@ -304,7 +310,7 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
             self.conn = None
 
 
             self.conn = None
 
 

-    def get_word_token_info(self, words):
+    def get_word_token_info(self, words: Sequence[str]) -> List[Tuple[str, str, int]]:

         """ Return token information for the given list of words.
             If a word starts with # it is assumed to be a full name
             otherwise is a partial name.
         """ Return token information for the given list of words.
             If a word starts with # it is assumed to be a full name
             otherwise is a partial name.


@@ -315,6 +321,7 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
             The function is used for testing and debugging only
             and not necessarily efficient.
         """
             The function is used for testing and debugging only
             and not necessarily efficient.
         """

+        assert self.conn is not None

         with self.conn.cursor() as cur:
             cur.execute("""SELECT t.term, word_token, word_id
                            FROM word, (SELECT unnest(%s::TEXT[]) as term) t
         with self.conn.cursor() as cur:
             cur.execute("""SELECT t.term, word_token, word_id
                            FROM word, (SELECT unnest(%s::TEXT[]) as term) t


@@ -330,14 +337,14 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
             return [(r[0], r[1], r[2]) for r in cur]
 
 
             return [(r[0], r[1], r[2]) for r in cur]
 
 

-    def normalize(self, phrase):
+    def normalize(self, phrase: str) -> str:

         """ Normalize the given phrase, i.e. remove all properties that
             are irrelevant for search.
         """
         """ Normalize the given phrase, i.e. remove all properties that
             are irrelevant for search.
         """

-        return self.normalizer.transliterate(phrase)
+        return cast(str, self.normalizer.transliterate(phrase))

 
 
 
 

-    def normalize_postcode(self, postcode):
+    def normalize_postcode(self, postcode: str) -> str:

         """ Convert the postcode to a standardized form.
 
             This function must yield exactly the same result as the SQL function
         """ Convert the postcode to a standardized form.
 
             This function must yield exactly the same result as the SQL function


@@ -346,10 +353,12 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
         return postcode.strip().upper()
 
 
         return postcode.strip().upper()
 
 

-    def update_postcodes_from_db(self):
+    def update_postcodes_from_db(self) -> None:

         """ Update postcode tokens in the word table from the location_postcode
             table.
         """
         """ Update postcode tokens in the word table from the location_postcode
             table.
         """

+        assert self.conn is not None
+

         with self.conn.cursor() as cur:
             # This finds us the rows in location_postcode and word that are
             # missing in the other table.
         with self.conn.cursor() as cur:
             # This finds us the rows in location_postcode and word that are
             # missing in the other table.


@@ -383,9 +392,12 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
 
 
 
 
 
 

-    def update_special_phrases(self, phrases, should_replace):
+    def update_special_phrases(self, phrases: Sequence[Tuple[str, str, str, str]],
+                               should_replace: bool) -> None:

         """ Replace the search index for special phrases with the new phrases.
         """
         """ Replace the search index for special phrases with the new phrases.
         """

+        assert self.conn is not None
+

         norm_phrases = set(((self.normalize(p[0]), p[1], p[2], p[3])
                             for p in phrases))
 
         norm_phrases = set(((self.normalize(p[0]), p[1], p[2], p[3])
                             for p in phrases))
 


@@ -422,9 +434,11 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
                  len(norm_phrases), len(to_add), len(to_delete))
 
 
                  len(norm_phrases), len(to_add), len(to_delete))
 
 

-    def add_country_names(self, country_code, names):
+    def add_country_names(self, country_code: str, names: Mapping[str, str]) -> None:

         """ Add names for the given country to the search index.
         """
         """ Add names for the given country to the search index.
         """

+        assert self.conn is not None
+

         with self.conn.cursor() as cur:
             cur.execute(
                 """INSERT INTO word (word_id, word_token, country_code)
         with self.conn.cursor() as cur:
             cur.execute(
                 """INSERT INTO word (word_id, word_token, country_code)


@@ -436,12 +450,14 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
                 """, (country_code, list(names.values()), country_code))
 
 
                 """, (country_code, list(names.values()), country_code))
 
 

-    def process_place(self, place):
+    def process_place(self, place: PlaceInfo) -> Mapping[str, Any]:

         """ Determine tokenizer information about the given place.
 
             Returns a JSON-serialisable structure that will be handed into
             the database via the token_info field.
         """
         """ Determine tokenizer information about the given place.
 
             Returns a JSON-serialisable structure that will be handed into
             the database via the token_info field.
         """

+        assert self.conn is not None
+

         token_info = _TokenInfo(self._cache)
 
         names = place.name
         token_info = _TokenInfo(self._cache)
 
         names = place.name


@@ -450,6 +466,7 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
             token_info.add_names(self.conn, names)
 
             if place.is_country():
             token_info.add_names(self.conn, names)
 
             if place.is_country():

+                assert place.country_code is not None

                 self.add_country_names(place.country_code, names)
 
         address = place.address
                 self.add_country_names(place.country_code, names)
 
         address = place.address


@@ -459,7 +476,8 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
         return token_info.data
 
 
         return token_info.data
 
 

-    def _process_place_address(self, token_info, address):
+    def _process_place_address(self, token_info: '_TokenInfo', address: Mapping[str, str]) -> None:
+        assert self.conn is not None

         hnrs = []
         addr_terms = []
 
         hnrs = []
         addr_terms = []
 


@@ -491,12 +509,12 @@ class LegacyNameAnalyzer(AbstractAnalyzer):
 class _TokenInfo:
     """ Collect token information to be sent back to the database.
     """
 class _TokenInfo:
     """ Collect token information to be sent back to the database.
     """

-    def __init__(self, cache):
+    def __init__(self, cache: '_TokenCache') -> None:

         self.cache = cache
         self.cache = cache

-        self.data = {}
+        self.data: Dict[str, Any] = {}

 
 
 
 

-    def add_names(self, conn, names):
+    def add_names(self, conn: Connection, names: Mapping[str, str]) -> None:

         """ Add token information for the names of the place.
         """
         with conn.cursor() as cur:
         """ Add token information for the names of the place.
         """
         with conn.cursor() as cur:


@@ -505,7 +523,7 @@ class _TokenInfo:
                                             (names, ))
 
 
                                             (names, ))
 
 

-    def add_housenumbers(self, conn, hnrs):
+    def add_housenumbers(self, conn: Connection, hnrs: Sequence[str]) -> None:

         """ Extract housenumber information from the address.
         """
         if len(hnrs) == 1:
         """ Extract housenumber information from the address.
         """
         if len(hnrs) == 1:


@@ -516,7 +534,7 @@ class _TokenInfo:
                 return
 
         # split numbers if necessary
                 return
 
         # split numbers if necessary

-        simple_list = []
+        simple_list: List[str] = []

         for hnr in hnrs:
             simple_list.extend((x.strip() for x in re.split(r'[;,]', hnr)))
 
         for hnr in hnrs:
             simple_list.extend((x.strip() for x in re.split(r'[;,]', hnr)))
 


@@ -525,49 +543,53 @@ class _TokenInfo:
 
         with conn.cursor() as cur:
             cur.execute("SELECT * FROM create_housenumbers(%s)", (simple_list, ))
 
         with conn.cursor() as cur:
             cur.execute("SELECT * FROM create_housenumbers(%s)", (simple_list, ))

-            self.data['hnr_tokens'], self.data['hnr'] = cur.fetchone()
+            self.data['hnr_tokens'], self.data['hnr'] = \
+                cur.fetchone() # type: ignore[no-untyped-call]

 
 
 
 

-    def set_postcode(self, postcode):
+    def set_postcode(self, postcode: str) -> None:

         """ Set or replace the postcode token with the given value.
         """
         self.data['postcode'] = postcode
 
         """ Set or replace the postcode token with the given value.
         """
         self.data['postcode'] = postcode
 

-    def add_street(self, conn, street):
+    def add_street(self, conn: Connection, street: str) -> None:

         """ Add addr:street match terms.
         """
         """ Add addr:street match terms.
         """

-        def _get_street(name):
+        def _get_street(name: str) -> List[int]:

             with conn.cursor() as cur:
             with conn.cursor() as cur:

-                return cur.scalar("SELECT word_ids_from_name(%s)::text", (name, ))
+                return cast(List[int],
+                            cur.scalar("SELECT word_ids_from_name(%s)::text", (name, )))

 
         tokens = self.cache.streets.get(street, _get_street)
         if tokens:
             self.data['street'] = tokens
 
 
 
         tokens = self.cache.streets.get(street, _get_street)
         if tokens:
             self.data['street'] = tokens
 
 

-    def add_place(self, conn, place):
+    def add_place(self, conn: Connection, place: str) -> None:

         """ Add addr:place search and match terms.
         """
         """ Add addr:place search and match terms.
         """

-        def _get_place(name):
+        def _get_place(name: str) -> Tuple[List[int], List[int]]:

             with conn.cursor() as cur:
                 cur.execute("""SELECT make_keywords(hstore('name' , %s))::text,
                                       word_ids_from_name(%s)::text""",
                             (name, name))
             with conn.cursor() as cur:
                 cur.execute("""SELECT make_keywords(hstore('name' , %s))::text,
                                       word_ids_from_name(%s)::text""",
                             (name, name))

-                return cur.fetchone()
+                return cast(Tuple[List[int], List[int]],
+                            cur.fetchone()) # type: ignore[no-untyped-call]

 
         self.data['place_search'], self.data['place_match'] = \
             self.cache.places.get(place, _get_place)
 
 
 
         self.data['place_search'], self.data['place_match'] = \
             self.cache.places.get(place, _get_place)
 
 

-    def add_address_terms(self, conn, terms):
+    def add_address_terms(self, conn: Connection, terms: Sequence[Tuple[str, str]]) -> None:

         """ Add additional address terms.
         """
         """ Add additional address terms.
         """

-        def _get_address_term(name):
+        def _get_address_term(name: str) -> Tuple[List[int], List[int]]:

             with conn.cursor() as cur:
                 cur.execute("""SELECT addr_ids_from_name(%s)::text,
                                       word_ids_from_name(%s)::text""",
                             (name, name))
             with conn.cursor() as cur:
                 cur.execute("""SELECT addr_ids_from_name(%s)::text,
                                       word_ids_from_name(%s)::text""",
                             (name, name))

-                return cur.fetchone()
+                return cast(Tuple[List[int], List[int]],
+                            cur.fetchone()) # type: ignore[no-untyped-call]

 
         tokens = {}
         for key, value in terms:
 
         tokens = {}
         for key, value in terms:


@@ -584,13 +606,12 @@ class _LRU:
         produce the item when there is a cache miss.
     """
 
         produce the item when there is a cache miss.
     """
 

-    def __init__(self, maxsize=128, init_data=None):
-        self.data = init_data or OrderedDict()
+    def __init__(self, maxsize: int = 128):
+        self.data: 'OrderedDict[str, Any]' = OrderedDict()

         self.maxsize = maxsize
         self.maxsize = maxsize

-        if init_data is not None and len(init_data) > maxsize:
-            self.maxsize = len(init_data)

 
 

-    def get(self, key, generator):
+
+    def get(self, key: str, generator: Callable[[str], Any]) -> Any:

         """ Get the item with the given key from the cache. If nothing
             is found in the cache, generate the value through the
             generator function and store it in the cache.
         """ Get the item with the given key from the cache. If nothing
             is found in the cache, generate the value through the
             generator function and store it in the cache.


@@ -613,7 +634,7 @@ class _TokenCache:
         This cache is not thread-safe and needs to be instantiated per
         analyzer.
     """
         This cache is not thread-safe and needs to be instantiated per
         analyzer.
     """

-    def __init__(self, conn):
+    def __init__(self, conn: Connection):

         # various LRU caches
         self.streets = _LRU(maxsize=256)
         self.places = _LRU(maxsize=128)
         # various LRU caches
         self.streets = _LRU(maxsize=256)
         self.places = _LRU(maxsize=128)


@@ -623,18 +644,18 @@ class _TokenCache:
         with conn.cursor() as cur:
             cur.execute("""SELECT i, ARRAY[getorcreate_housenumber_id(i::text)]::text
                            FROM generate_series(1, 100) as i""")
         with conn.cursor() as cur:
             cur.execute("""SELECT i, ARRAY[getorcreate_housenumber_id(i::text)]::text
                            FROM generate_series(1, 100) as i""")

-            self._cached_housenumbers = {str(r[0]): r[1] for r in cur}
+            self._cached_housenumbers: Dict[str, str] = {str(r[0]): r[1] for r in cur}

 
         # For postcodes remember the ones that have already been added
 
         # For postcodes remember the ones that have already been added

-        self.postcodes = set()
+        self.postcodes: Set[str] = set()

 
 

-    def get_housenumber(self, number):
+    def get_housenumber(self, number: str) -> Optional[str]:

         """ Get a housenumber token from the cache.
         """
         return self._cached_housenumbers.get(number)
 
 
         """ Get a housenumber token from the cache.
         """
         return self._cached_housenumbers.get(number)
 
 

-    def add_postcode(self, conn, postcode):
+    def add_postcode(self, conn: Connection, postcode: str) -> None:

         """ Make sure the given postcode is in the database.
         """
         if postcode not in self.postcodes:
         """ Make sure the given postcode is in the database.
         """
         if postcode not in self.postcodes: