use __import__() to dynamically load modules

gallery_dl/downloader/__init__.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2019 Mike Fährmann
+# Copyright 2015-2021 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -8,8 +8,6 @@
 
 """Downloader modules"""
 
-import importlib
-
 modules = [
     "http",
     "text",
@@ -24,22 +22,22 @@ def find(scheme):
     except KeyError:
         pass
 
-    klass = None
+    cls = None
     if scheme == "https":
         scheme = "http"
     if scheme in modules:  # prevent unwanted imports
         try:
-            module = importlib.import_module("." + scheme, __package__)
+            module = __import__(scheme, globals(), None, (), 1)
         except ImportError:
             pass
         else:
-            klass = module.__downloader__
+            cls = module.__downloader__
 
     if scheme == "http":
-        _cache["http"] = _cache["https"] = klass
+        _cache["http"] = _cache["https"] = cls
     else:
-        _cache[scheme] = klass
-    return klass
+        _cache[scheme] = cls
+    return cls
 
 
 # --------------------------------------------------------------------

gallery_dl/extractor/__init__.py

@@ -7,7 +7,6 @@
 # published by the Free Software Foundation.
 
 import re
-import importlib
 
 modules = [
     "2chan",
@@ -185,11 +184,12 @@ def _list_classes():
     """Yield all available extractor classes"""
     yield from _cache
 
+    globals_ = globals()
     for module_name in _module_iter:
-        module = importlib.import_module("."+module_name, __package__)
+        module = __import__(module_name, globals_, None, (), 1)
         yield from add_module(module)
 
-    globals()["_list_classes"] = lambda : _cache
+    globals_["_list_classes"] = lambda : _cache
 
 
 def _get_classes(module):

gallery_dl/postprocessor/__init__.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2018-2020 Mike Fährmann
+# Copyright 2018-2021 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -8,8 +8,6 @@
 
 """Post-processing modules"""
 
-import importlib
-
 modules = [
     "classify",
     "compare",
@@ -28,16 +26,16 @@ def find(name):
     except KeyError:
         pass
 
-    klass = None
+    cls = None
     if name in modules:  # prevent unwanted imports
         try:
-            module = importlib.import_module("." + name, __package__)
+            module = __import__(name, globals(), None, (), 1)
         except ImportError:
             pass
         else:
-            klass = module.__postprocessor__
-    _cache[name] = klass
-    return klass
+            cls = module.__postprocessor__
+    _cache[name] = cls
+    return cls
 
 
 # --------------------------------------------------------------------

test/test_downloader.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-# Copyright 2018-2020 Mike Fährmann
+# Copyright 2018-2021 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -74,7 +74,7 @@ class TestDownloaderModule(unittest.TestCase):
         self.assertEqual(downloader.find(1234) , None)
         self.assertEqual(downloader.find(None) , None)
 
-    @patch("importlib.import_module")
+    @patch("builtins.__import__")
     def test_cache(self, import_module):
         import_module.return_value = MockDownloaderModule()
         downloader.find("http")
@@ -86,14 +86,14 @@ class TestDownloaderModule(unittest.TestCase):
         downloader.find("ytdl")
         self.assertEqual(import_module.call_count, 3)
 
-    @patch("importlib.import_module")
+    @patch("builtins.__import__")
     def test_cache_http(self, import_module):
         import_module.return_value = MockDownloaderModule()
         downloader.find("http")
         downloader.find("https")
         self.assertEqual(import_module.call_count, 1)
 
-    @patch("importlib.import_module")
+    @patch("builtins.__import__")
     def test_cache_https(self, import_module):
         import_module.return_value = MockDownloaderModule()
         downloader.find("https")

test/test_postprocessor.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-# Copyright 2019-2020 Mike Fährmann
+# Copyright 2019-2021 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -53,7 +53,7 @@ class TestPostprocessorModule(unittest.TestCase):
         self.assertEqual(postprocessor.find(1234) , None)
         self.assertEqual(postprocessor.find(None) , None)
 
-    @patch("importlib.import_module")
+    @patch("builtins.__import__")
     def test_cache(self, import_module):
         import_module.return_value = MockPostprocessorModule()