X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/4665ea3e773b5620f5b65cf2396a91192cc8cda0..6cf1287c4e7f7f7ef6af8489ccb54a213bf7571a:/src/nominatim_api/query_preprocessing/regex_replace.py?ds=inline

diff --git a/src/nominatim_api/query_preprocessing/regex_replace.py b/src/nominatim_api/query_preprocessing/regex_replace.py
index 883fa991..b3a02495 100644
--- a/src/nominatim_api/query_preprocessing/regex_replace.py
+++ b/src/nominatim_api/query_preprocessing/regex_replace.py
@@ -5,7 +5,11 @@
 # Copyright (C) 2025 by the Nominatim developer community.
 # For a full list of authors see the git log.
 """
-This file replaces values based on pre-defined regex rules:
+This preprocessor replaces values in a given input based on pre-defined regex rules.
+
+Arguments:
+    pattern: Regex pattern to be applied on the input
+    replace: The string that it is to be replaced with
 """
 from typing import List
 import re
@@ -16,31 +20,33 @@ from ..search.query import Phrase
 
 
 class _GenericPreprocessing:
+    """Perform replacements to input phrases using custom regex patterns."""
 
     def __init__(self, config: QueryConfig) -> None:
+        """Initialise the _GenericPreprocessing class with patterns from the ICU config file."""
         self.config = config
 
-    def split_phrase(self, phrase: Phrase) -> Phrase:
-        """
-        This function performs replacements on the given text using regex patterns.
-        """
-
-        if phrase.text is None:
-            return phrase
-
         match_patterns = self.config.get('replacements', 'Key not found')
-        for item in match_patterns:
-            phrase.text = re.sub(item['pattern'], item['replace'], phrase.text)
+        self.compiled_patterns = [
+            (re.compile(item['pattern']), item['replace']) for item in match_patterns
+            ]
+
+    def split_phrase(self, phrase: Phrase) -> Phrase:
+        """This function performs replacements on the given text using regex patterns."""
+        for item in self.compiled_patterns:
+            phrase.text = item[0].sub(item[1], phrase.text)
 
         return phrase
 
     def __call__(self, phrases: List[Phrase]) -> List[Phrase]:
-        """Apply regex replacements to the given addresses.
         """
-        return [self.split_phrase(p) for p in phrases]
+        Return the final Phrase list.
+        Returns an empty list if there is nothing left after split_phrase.
+        """
+        result = [p for p in map(self.split_phrase, phrases) if p.text.strip()]
+        return result
 
 
 def create(config: QueryConfig) -> QueryProcessingFunc:
-    """ Create a function for generic preprocessing.
-    """
+    """ Create a function for generic preprocessing."""
     return _GenericPreprocessing(config)