Don't use deprecated load_module

Closes #227

gaupol/extensionman.py

@@ -19,7 +19,6 @@
 
 import aeidon
 import gaupol
-import importlib.machinery
 import inspect
 import os
 import re
@@ -122,8 +121,7 @@ def setup_extension(self, module, slave=False):
         directory = os.path.dirname(metadata.path)
         name = "gaupol.extension.{:s}".format(module)
         path = os.path.join(directory, "{}.py".format(module))
-        loader = importlib.machinery.SourceFileLoader(name, path)
-        module_object = loader.load_module(name)
+        module_object = gaupol.util.load_module_from_file(name, path)
         for attribute in dir(module_object):
             if attribute.startswith("_"): continue
             value = getattr(module_object, attribute)

gaupol/util.py

@@ -19,6 +19,7 @@
 
 import aeidon
 import gaupol
+import importlib.util
 import inspect
 import sys
 import traceback
@@ -227,6 +228,14 @@ def lines_to_px(nlines, font=None):
     height = label.get_preferred_height()[1]
     return int(round(nlines * height))
 
+def load_module_from_file(name, path):
+    # https://docs.python.org/3/library/importlib.html#importing-a-source-file-directly
+    spec = importlib.util.spec_from_file_location(name, path)
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[name] = module
+    spec.loader.exec_module(module)
+    return module
+
 def new_hbox(spacing):
     """Return a new horizontal :class:`Gtk.Box`."""
     return Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL,