Add public functions to add custom external plugin paths

test/test_plugins.py

@@ -5,6 +5,7 @@ import sys
 import unittest
 from pathlib import Path
 import yt_dlp._globals
+from yt_dlp.plugins import set_plugin_dirs, add_plugin_dirs, PluginDirs
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 TEST_DATA_DIR = Path(os.path.dirname(os.path.abspath(__file__)), 'testdata')
@@ -37,7 +38,7 @@ class TestPlugins(unittest.TestCase):
     def setUp(self):
         plugin_ies.set({})
         plugin_pps.set({})
-        plugin_dirs.set((...,))
+        plugin_dirs.set((PluginDirs.DEFAULT_EXTERNAL,))
         plugin_specs.set({})
         all_plugins_loaded.set(False)
         importlib.invalidate_caches()
@@ -174,8 +175,25 @@ class TestPlugins(unittest.TestCase):
         self.assertIn(f'{PACKAGE_NAME}.extractor.normal', sys.modules.keys())
         self.assertIn(f'{PACKAGE_NAME}.postprocessor.normal', sys.modules.keys())
 
-    def test_plugin_dirs(self):
-        plugin_dirs.set((..., str(TEST_DATA_DIR / 'plugin_packages')))
+    def test_set_plugin_dirs(self):
+
+        custom_plugin_dir = str(TEST_DATA_DIR / 'plugin_packages')
+        set_plugin_dirs(custom_plugin_dir)
+
+        self.assertEqual(plugin_dirs.get(), (custom_plugin_dir, ))
+        self.assertNotIn('external', plugin_dirs.get())
+        load_plugins(EXTRACTOR_PLUGIN_SPEC)
+
+        self.assertIn(f'{PACKAGE_NAME}.extractor.package', sys.modules.keys())
+        self.assertIn('PackagePluginIE', plugin_ies.get())
+
+    def test_add_plugin_dirs(self):
+        custom_plugin_dir = str(TEST_DATA_DIR / 'plugin_packages')
+
+        self.assertEqual(plugin_dirs.get(), (PluginDirs.DEFAULT_EXTERNAL,))
+        add_plugin_dirs(custom_plugin_dir)
+        self.assertEqual(plugin_dirs.get(), (PluginDirs.DEFAULT_EXTERNAL, custom_plugin_dir))
+
         load_plugins(EXTRACTOR_PLUGIN_SPEC)
 
         self.assertIn(f'{PACKAGE_NAME}.extractor.package', sys.modules.keys())

yt_dlp/__init__.py

@@ -20,9 +20,11 @@ from .downloader.external import get_external_downloader
 from .extractor import list_extractor_classes
 from .extractor.adobepass import MSO_INFO
 from .networking.impersonate import ImpersonateTarget
-from ._globals import IN_CLI, plugin_dirs
+from ._globals import IN_CLI as _IN_CLI
 from .options import parseOpts
-from .plugins import load_all_plugins
+from .plugins import load_all_plugins as _load_all_plugins
+from .plugins import PluginDirs as _PluginDirs
+from .plugins import set_plugin_dirs as _set_plugin_dirs
 from .postprocessor import (
     FFmpegExtractAudioPP,
     FFmpegMergerPP,
@@ -428,8 +430,8 @@ def validate_options(opts):
 
     # Other options
     opts.plugin_dirs = opts.plugin_dirs or []
-    if 'no-default' not in opts.plugin_dirs:
-        opts.plugin_dirs.append(...)
+    if 'no-external' not in opts.plugin_dirs:
+        opts.plugin_dirs.append(_PluginDirs.DEFAULT_EXTERNAL)
 
     if opts.playlist_items is not None:
         try:
@@ -986,8 +988,8 @@ def _real_main(argv=None):
         FFmpegPostProcessor._ffmpeg_location.set(opts.ffmpeg_location)
 
     # load all plugins into the global lookup
-    plugin_dirs.set(opts.plugin_dirs)
-    load_all_plugins()
+    _set_plugin_dirs(*opts.plugin_dirs)
+    _load_all_plugins()
 
     with YoutubeDL(ydl_opts) as ydl:
         pre_process = opts.update_self or opts.rm_cachedir
@@ -1088,7 +1090,7 @@ def _real_main(argv=None):
 
 
 def main(argv=None):
-    IN_CLI.set(True)
+    _IN_CLI.set(True)
     try:
         _exit(*variadic(_real_main(argv)))
     except (CookieLoadError, DownloadError):

yt_dlp/_globals.py

@@ -17,8 +17,7 @@ plugin_specs = ContextVar('plugin_specs', default={})
 # Whether plugins have been loaded once
 all_plugins_loaded = ContextVar('all_plugins_loaded', default=False)
 
-# `...`=search default plugin dirs
-plugin_dirs = ContextVar('plugin_dirs', default=(..., ))
+plugin_dirs = ContextVar('plugin_dirs', default=('external', ))
 plugin_ies = ContextVar('plugin_ies', default={})
 plugin_overrides = ContextVar('plugin_overrides', default=defaultdict(list))
 plugin_pps = ContextVar('plugin_pps', default={})

yt_dlp/options.py

@@ -472,7 +472,7 @@ def create_parser():
         action='append',
         help=(
             'Directory to search for plugins. Can be used multiple times to add multiple directories. '
-            'Add "no-default" to disable the default plugin directories'
+            'Add "no-external" to disable searching default external plugin directories (outside of python environment)'
         ),
     )
     general.add_option(

yt_dlp/plugins.py

@@ -1,5 +1,6 @@
 import contextlib
 import dataclasses
+import enum
 import importlib
 import importlib.abc
 import importlib.machinery
@@ -36,6 +37,26 @@ COMPAT_PACKAGE_NAME = 'ytdlp_plugins'
 _BASE_PACKAGE_PATH = Path(__file__).parent
 
 
+# Public APIs
+# Anything else is NOT public and no backwards compatibility is guaranteed
+__all__ = [
+    'directories',
+    'load_plugins',
+    'load_all_plugins',
+    'register_plugin_spec',
+    'add_plugin_dirs',
+    'set_plugin_dirs',
+    'PluginDirs',
+    'get_plugin_spec',
+    'PACKAGE_NAME',
+    'COMPAT_PACKAGE_NAME',
+]
+
+
+class PluginDirs(enum.Enum):
+    DEFAULT_EXTERNAL = 'external'  # The default external plugin directories
+
+
 @dataclasses.dataclass
 class PluginSpec:
     module_name: str
@@ -114,7 +135,7 @@ class PluginFinder(importlib.abc.MetaPathFinder):
 
     def search_locations(self, fullname):
         candidate_locations = itertools.chain.from_iterable(
-            external_plugin_paths() if candidate is ... else Path(candidate).iterdir()
+            external_plugin_paths() if candidate == PluginDirs.DEFAULT_EXTERNAL else Path(candidate).iterdir()
             for candidate in plugin_dirs.get()
         )
 
@@ -203,7 +224,7 @@ def load_plugins(plugin_spec: PluginSpec):
     # Compat: old plugin system using __init__.py
     # Note: plugins imported this way do not show up in directories()
     # nor are considered part of the yt_dlp_plugins namespace package
-    if ... in plugin_dirs.get((...,)):
+    if PluginDirs.DEFAULT_EXTERNAL in plugin_dirs.get():
         with contextlib.suppress(FileNotFoundError):
             spec = importlib.util.spec_from_file_location(
                 name,
@@ -235,16 +256,15 @@ def register_plugin_spec(plugin_spec: PluginSpec):
         sys.meta_path.insert(0, PluginFinder(f'{PACKAGE_NAME}.{plugin_spec.module_name}'))
 
 
+def add_plugin_dirs(*paths):
+    """Add external plugin dirs to the existing ones"""
+    plugin_dirs.set((*plugin_dirs.get(), *paths))
+
+
+def set_plugin_dirs(*paths):
+    """Set external plugin dirs, overriding the default ones"""
+    plugin_dirs.set(tuple(paths))
+
+
 def get_plugin_spec(module_name):
     return plugin_specs.get().get(module_name)
-
-
-__all__ = [
-    'directories',
-    'load_plugins',
-    'load_all_plugins',
-    'register_plugin_spec',
-    'get_plugin_spec',
-    'PACKAGE_NAME',
-    'COMPAT_PACKAGE_NAME',
-]