[utils] Introduce merge_dicts

test/test_utils.py

@@ -42,6 +42,7 @@ from youtube_dl.utils import (
     is_html,
     js_to_json,
     limit_length,
+    merge_dicts,
     mimetype2ext,
     month_by_name,
     multipart_encode,
@@ -669,6 +670,17 @@ class TestUtil(unittest.TestCase):
             self.assertEqual(dict_get(d, ('b', 'c', key, )), None)
             self.assertEqual(dict_get(d, ('b', 'c', key, ), skip_false_values=False), false_value)
 
+    def test_merge_dicts(self):
+        self.assertEqual(merge_dicts({'a': 1}, {'b': 2}), {'a': 1, 'b': 2})
+        self.assertEqual(merge_dicts({'a': 1}, {'a': 2}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': 1}, {'a': None}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': 1}, {'a': ''}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': 1}, {}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': None}, {'a': 1}), {'a': 1})
+        self.assertEqual(merge_dicts({'a': ''}, {'a': 1}), {'a': ''})
+        self.assertEqual(merge_dicts({'a': ''}, {'a': 'abc'}), {'a': 'abc'})
+        self.assertEqual(merge_dicts({'a': None}, {'a': ''}, {'a': 'abc'}), {'a': 'abc'})
+
     def test_encode_compat_str(self):
         self.assertEqual(encode_compat_str(b'\xd1\x82\xd0\xb5\xd1\x81\xd1\x82', 'utf-8'), 'тест')
         self.assertEqual(encode_compat_str('тест', 'utf-8'), 'тест')

youtube_dl/extractor/generic.py

@@ -23,6 +23,7 @@ from ..utils import (
     is_html,
     js_to_json,
     KNOWN_EXTENSIONS,
+    merge_dicts,
     mimetype2ext,
     orderedSet,
     sanitized_Request,
@@ -3002,21 +3003,6 @@ class GenericIE(InfoExtractor):
             return self.playlist_from_matches(
                 sharevideos_urls, video_id, video_title)
 
-        def merge_dicts(dict1, dict2):
-            merged = {}
-            for k, v in dict1.items():
-                if v is not None:
-                    merged[k] = v
-            for k, v in dict2.items():
-                if v is None:
-                    continue
-                if (k not in merged or
-                        (isinstance(v, compat_str) and v and
-                            isinstance(merged[k], compat_str) and
-                            not merged[k])):
-                    merged[k] = v
-            return merged
-
         # Look for HTML5 media
         entries = self._parse_html5_media_entries(url, webpage, video_id, m3u8_id='hls')
         if entries:

youtube_dl/utils.py

@@ -2225,6 +2225,20 @@ def try_get(src, getter, expected_type=None):
                 return v
 
 
+def merge_dicts(*dicts):
+    merged = {}
+    for a_dict in dicts:
+        for k, v in a_dict.items():
+            if v is None:
+                continue
+            if (k not in merged or
+                    (isinstance(v, compat_str) and v and
+                        isinstance(merged[k], compat_str) and
+                        not merged[k])):
+                merged[k] = v
+    return merged
+
+
 def encode_compat_str(string, encoding=preferredencoding(), errors='strict'):
     return string if isinstance(string, compat_str) else compat_str(string, encoding, errors)