[ytdl] support specifying filesystem paths as 'module' (#6991)

docs/configuration.rst

@@ -5184,11 +5184,15 @@ Description
 extractor.ytdl.module
 ---------------------
 Type
-    ``string``
+    * ``string``
+    * |Path|_
 Default
     ``null``
+Example
+    * ``"yt-dlp"``
+    * ``"/home/user/.local/lib/python3.13/site-packages/youtube_dl"``
 Description
-    Name of the ``ytdl`` Python module to import.
+    Name or filesystem path of the ``ytdl`` Python module to import.
 
     Setting this to ``null`` will try to import ``"yt_dlp"``
     followed by ``"youtube_dl"`` as fallback.
@@ -5644,11 +5648,15 @@ Description
 downloader.ytdl.module
 ----------------------
 Type
-    ``string``
+    * ``string``
+    * |Path|_
 Default
     ``null``
+Example
+    * ``"yt-dlp"``
+    * ``"/home/user/.local/lib/python3.13/site-packages/youtube_dl"``
 Description
-    Name of the ``ytdl`` Python module to import.
+    Name or filesystem path of the ``ytdl`` Python module to import.
 
     Setting this to ``null`` will try to import ``"yt_dlp"``
     followed by ``"youtube_dl"`` as fallback.

gallery_dl/util.py

@@ -770,7 +770,7 @@ def import_file(path):
         finally:
             del sys.path[0]
     else:
-        return __import__(name)
+        return __import__(name.replace("-", "_"))
 
 
 def build_duration_func(duration, min=0.0):

gallery_dl/ytdl.py

@@ -20,7 +20,7 @@ def import_module(module_name):
             return __import__("yt_dlp")
         except (ImportError, SyntaxError):
             return __import__("youtube_dl")
-    return __import__(module_name.replace("-", "_"))
+    return util.import_file(module_name)
 
 
 def construct_YoutubeDL(module, obj, user_opts, system_opts=None):