convert special phrase loaders to generators

Generators simplify the code quite a bit compared to the previous
Iterator approach.

nominatim/tools/special_phrases/sp_csv_loader.py

@@ -11,43 +11,31 @@
 """
 import csv
 import os
-from collections.abc import Iterator
 from nominatim.tools.special_phrases.special_phrase import SpecialPhrase
 from nominatim.errors import UsageError
 
-class SPCsvLoader(Iterator):
+class SPCsvLoader:
     """
         Handles loading of special phrases from external csv file.
     """
     def __init__(self, csv_path):
         super().__init__()
         self.csv_path = csv_path
-        self.has_been_read = False
 
-    def __next__(self):
-        if self.has_been_read:
-            raise StopIteration()
 
-        self.has_been_read = True
+    def generate_phrases(self):
-        self.check_csv_validity()
+        """ Open and parse the given csv file.
-        return self.parse_csv()
-
-    def parse_csv(self):
-        """
-            Open and parse the given csv file.
             Create the corresponding SpecialPhrases.
         """
-        phrases = set()
+        self._check_csv_validity()
 
         with open(self.csv_path, encoding='utf-8') as fd:
             reader = csv.DictReader(fd, delimiter=',')
             for row in reader:
-                phrases.add(
+                yield SpecialPhrase(row['phrase'], row['class'], row['type'], row['operator'])
-                    SpecialPhrase(row['phrase'], row['class'], row['type'], row['operator'])
-                )
-        return phrases
 
-    def check_csv_validity(self):
+
+    def _check_csv_validity(self):
         """
             Check that the csv file has the right extension.
         """

nominatim/tools/special_phrases/sp_importer.py

@@ -62,8 +62,7 @@ class SPImporter():
         # Store pairs of class/type for further processing
         class_type_pairs = set()
 
-        for loaded_phrases in self.sp_loader:
+        for phrase in self.sp_loader.generate_phrases():
-            for phrase in loaded_phrases:
             result = self._process_phrase(phrase)
             if result:
                 class_type_pairs.add(result)

nominatim/tools/special_phrases/sp_wiki_loader.py

@@ -9,12 +9,24 @@
 """
 import re
 import logging
-from collections.abc import Iterator
 from nominatim.tools.special_phrases.special_phrase import SpecialPhrase
 from nominatim.tools.exec_utils import get_url
 
 LOG = logging.getLogger()
-class SPWikiLoader(Iterator):
+
+def _get_wiki_content(lang):
+    """
+        Request and return the wiki page's content
+        corresponding to special phrases for a given lang.
+        Requested URL Example :
+            https://wiki.openstreetmap.org/wiki/Special:Export/Nominatim/Special_Phrases/EN
+    """
+    url = 'https://wiki.openstreetmap.org/wiki/Special:Export/Nominatim/Special_Phrases/' \
+          + lang.upper()
+    return get_url(url)
+
+
+class SPWikiLoader:
     """
         Handles loading of special phrases from the wiki.
     """
@@ -27,28 +39,21 @@ class SPWikiLoader(Iterator):
         )
         self._load_languages()
 
-    def __next__(self):
-        if not self.languages:
-            raise StopIteration
 
-        lang = self.languages.pop(0)
+    def generate_phrases(self):
-        loaded_xml = self._get_wiki_content(lang)
+        """ Download the wiki pages for the configured languages
+            and extract the phrases from the page.
+        """
+        for lang in self.languages:
             LOG.warning('Importing phrases for lang: %s...', lang)
-        return self.parse_xml(loaded_xml)
+            loaded_xml = _get_wiki_content(lang)
 
-    def parse_xml(self, xml):
-        """
-            Parses XML content and extracts special phrases from it.
-            Return a list of SpecialPhrase.
-        """
             # One match will be of format [label, class, type, operator, plural]
-        matches = self.occurence_pattern.findall(xml)
+            matches = self.occurence_pattern.findall(loaded_xml)
-        returned_phrases = set()
+
             for match in matches:
-            returned_phrases.add(
+                yield SpecialPhrase(match[0], match[1], match[2], match[3])
-                SpecialPhrase(match[0], match[1], match[2], match[3])
+
-            )
-        return returned_phrases
 
     def _load_languages(self):
         """
@@ -64,15 +69,3 @@ class SPWikiLoader(Iterator):
             'et', 'eu', 'fa', 'fi', 'fr', 'gl', 'hr', 'hu',
             'ia', 'is', 'it', 'ja', 'mk', 'nl', 'no', 'pl',
             'ps', 'pt', 'ru', 'sk', 'sl', 'sv', 'uk', 'vi']
-
-    @staticmethod
-    def _get_wiki_content(lang):
-        """
-            Request and return the wiki page's content
-            corresponding to special phrases for a given lang.
-            Requested URL Example :
-                https://wiki.openstreetmap.org/wiki/Special:Export/Nominatim/Special_Phrases/EN
-        """
-        url = 'https://wiki.openstreetmap.org/wiki/Special:Export/Nominatim/Special_Phrases/' \
-              + lang.upper()
-        return get_url(url)

test/python/tools/test_import_special_phrases.py

@@ -187,8 +187,8 @@ def test_import_phrases(monkeypatch, temp_db_conn, def_config, sp_importer,
     table_factory('place_classtype_amenity_animal_shelter')
     table_factory('place_classtype_wrongclass_wrongtype')
 
-    monkeypatch.setattr('nominatim.tools.special_phrases.sp_wiki_loader.SPWikiLoader._get_wiki_content',
+    monkeypatch.setattr('nominatim.tools.special_phrases.sp_wiki_loader._get_wiki_content',
-                        lambda self, lang: xml_wiki_content)
+                        lambda lang: xml_wiki_content)
 
     tokenizer = tokenizer_mock()
     sp_importer.import_phrases(tokenizer, should_replace)

test/python/tools/test_sp_csv_loader.py

@@ -12,50 +12,6 @@ import pytest
 from nominatim.errors import UsageError
 from nominatim.tools.special_phrases.sp_csv_loader import SPCsvLoader
 
-def test_parse_csv(sp_csv_loader):
-    """
-        Test method parse_csv()
-        Should return the right SpecialPhrase objects.
-    """
-    phrases = sp_csv_loader.parse_csv()
-    assert check_phrases_content(phrases)
-
-def test_next(sp_csv_loader):
-    """
-        Test objects returned from the next() method.
-        It should return all SpecialPhrases objects of
-        the sp_csv_test.csv special phrases.
-    """
-    phrases = next(sp_csv_loader)
-    assert check_phrases_content(phrases)
-
-def test_check_csv_validity(sp_csv_loader):
-    """
-        Test method check_csv_validity()
-        It should raise an exception when file with a
-        different exception than .csv is given.
-    """
-    sp_csv_loader.csv_path = 'test.csv'
-    sp_csv_loader.check_csv_validity()
-    sp_csv_loader.csv_path = 'test.wrong'
-    with pytest.raises(UsageError):
-        assert sp_csv_loader.check_csv_validity()
-
-def check_phrases_content(phrases):
-    """
-        Asserts that the given phrases list contains
-        the right phrases of the sp_csv_test.csv special phrases.
-    """
-    return  len(phrases) > 1 \
-            and any(p.p_label == 'Billboard'
-                    and p.p_class == 'advertising'
-                    and p.p_type == 'billboard'
-                    and p.p_operator == '-' for p in phrases) \
-            and any(p.p_label == 'Zip Lines'
-                    and p.p_class == 'aerialway'
-                    and p.p_type == 'zip_line'
-                    and p.p_operator == '-' for p in phrases)
-
 @pytest.fixture
 def sp_csv_loader(src_dir):
     """
@@ -64,3 +20,35 @@ def sp_csv_loader(src_dir):
     csv_path = (src_dir / 'test' / 'testdata' / 'sp_csv_test.csv').resolve()
     loader = SPCsvLoader(csv_path)
     return loader
+
+
+def test_generate_phrases(sp_csv_loader):
+    """
+        Test method parse_csv()
+        Should return the right SpecialPhrase objects.
+    """
+    phrases = list(sp_csv_loader.generate_phrases())
+
+    assert len(phrases) == 41
+    assert len(set(phrases)) == 41
+
+    assert any(p.p_label == 'Billboard'
+               and p.p_class == 'advertising'
+               and p.p_type == 'billboard'
+               and p.p_operator == '-' for p in phrases)
+    assert any(p.p_label == 'Zip Lines'
+               and p.p_class == 'aerialway'
+               and p.p_type == 'zip_line'
+               and p.p_operator == '-' for p in phrases)
+
+
+def test_invalid_cvs_file():
+    """
+        Test method check_csv_validity()
+        It should raise an exception when file with a
+        different exception than .csv is given.
+    """
+    loader = SPCsvLoader('test.wrong')
+
+    with pytest.raises(UsageError, match='not a csv file'):
+        next(loader.generate_phrases())

test/python/tools/test_sp_wiki_loader.py

@@ -26,27 +26,18 @@ def sp_wiki_loader(monkeypatch, def_config, xml_wiki_content):
     """
     monkeypatch.setenv('NOMINATIM_LANGUAGES', 'en')
     loader = SPWikiLoader(def_config)
-    monkeypatch.setattr('nominatim.tools.special_phrases.sp_wiki_loader.SPWikiLoader._get_wiki_content',
+    monkeypatch.setattr('nominatim.tools.special_phrases.sp_wiki_loader._get_wiki_content',
-                        lambda self, lang: xml_wiki_content)
+                        lambda lang: xml_wiki_content)
     return loader
 
 
-def test_parse_xml(sp_wiki_loader, xml_wiki_content):
+def test_generate_phrases(sp_wiki_loader):
-    """
-        Test method parse_xml()
-        Should return the right SpecialPhrase objects.
-    """
-    phrases = sp_wiki_loader.parse_xml(xml_wiki_content)
-    check_phrases_content(phrases)
-
-
-def test_next(sp_wiki_loader):
     """
         Test objects returned from the next() method.
         It should return all SpecialPhrases objects of
         the 'en' special phrases.
     """
-    phrases = next(sp_wiki_loader)
+    phrases = list(sp_wiki_loader.generate_phrases())
     check_phrases_content(phrases)
 
 def check_phrases_content(phrases):