factor out housenumber splitting into sanitizer

nominatim/tokenizer/sanitizers/clean_housenumbers.py

@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
+"""
+Sanitizer that cleans and normalizes housenumbers.
+"""
+import re
+
+class _HousenumberSanitizer:
+
+    def __init__(self, config):
+        pass
+
+
+    def __call__(self, obj):
+        if not obj.address:
+            return
+
+        new_address = []
+        for item in obj.address:
+            if item.kind in ('housenumber', 'streetnumber', 'conscriptionnumber'):
+                new_address.extend(item.clone(kind='housenumber', name=n) for n in self.sanitize(item.name))
+            else:
+                # Don't touch other address items.
+                new_address.append(item)
+
+        obj.address = new_address
+
+
+    def sanitize(self, value):
+        """ Extract housenumbers in a regularized format from an OSM value.
+
+            The function works as a generator that yields all valid housenumbers
+            that can be created from the value.
+        """
+        for hnr in self._split_number(value):
+            yield from self._regularize(hnr)
+
+
+    def _split_number(self, hnr):
+        for part in re.split(r'[;,]', hnr):
+            yield part.strip()
+
+
+    def _regularize(self, hnr):
+        yield hnr
+
+
+def create(config):
+    """ Create a housenumber processing function.
+    """
+
+    return _HousenumberSanitizer(config)