feat: Add double metaphone phonetic matcher (#55)

Co-authored-by: Guy Korland <gkorland@gmail.com>

Author: joeirimpan

redisearch/client.py

@@ -21,6 +21,7 @@ class Field(object):
     SORTABLE = 'SORTABLE'
     NOINDEX = 'NOINDEX'
     SEPARATOR = 'SEPARATOR'
+    PHONETIC = 'PHONETIC'
 
     def __init__(self, name, *args):
         self.name = name
@@ -37,14 +38,17 @@ class TextField(Field):
     NOSTEM = 'NOSTEM'
 
     def __init__(self, name, weight=1.0, sortable=False, no_stem=False,
-                 no_index=False):
+                 no_index=False, phonetic_matcher=None):
         args = [Field.TEXT, Field.WEIGHT, weight]
         if no_stem:
             args.append(self.NOSTEM)
         if sortable:
             args.append(Field.SORTABLE)
         if no_index:
             args.append(self.NOINDEX)
+        if phonetic_matcher and phonetic_matcher in ['dm:en', 'dm:fr', 'dm:pt', 'dm:es']:
+            args.append(self.PHONETIC)
+            args.append(phonetic_matcher)
 
         if no_index and not sortable:
             raise ValueError('Non-Sortable non-Indexable fields are ignored')

test/test.py

@@ -568,6 +568,35 @@ def testDictOps(self):
             # Remove rest of the items before reload
             client.dict_del('custom_dict', *res)
 
+    def testPhoneticMatcher(self):
+        conn = self.redis()
+
+        with conn as r:
+            # Creating a client with a given index name
+            client = Client('myIndex', port=conn.port)
+            client.redis.flushdb()
+
+            client.create_index((TextField('name'),))
+
+            client.add_document('doc1', name='Jon')
+            client.add_document('doc2', name='John')
+
+            res = client.search(Query("Jon"))
+            self.assertEqual(1, len(res.docs))
+            self.assertEqual('Jon', res.docs[0].name)
+
+            # Drop and create index with phonetic matcher
+            client.redis.flushdb()
+
+            client.create_index((TextField('name', phonetic_matcher='dm:en'),))
+
+            client.add_document('doc1', name='Jon')
+            client.add_document('doc2', name='John')
+
+            res = client.search(Query("Jon"))
+            self.assertEqual(2, len(res.docs))
+            self.assertEqual(['John', 'Jon'], sorted([d.name for d in res.docs]))
+            
     def testGet(self):
         client = self.getCleanClient('idx')
         client.create_index((TextField('f1'), TextField('f2')))