Use importlib instead of imp

... because the imp module is deprecated since Python 3.4 .

Closes-Bug: #1937904
Change-Id: Ib8f06ee629753faec73cf3a2f41e7c743b6e0b04

os_win/tests/unit/utils/test_baseutils.py

@@ -16,7 +16,7 @@ from unittest import mock
 
 import six
 
-import imp
+import importlib
 
 from os_win.tests.unit import test_base
 from os_win.utils import baseutils
@@ -29,7 +29,7 @@ class BaseUtilsTestCase(test_base.OsWinBaseTestCase):
         super(BaseUtilsTestCase, self).setUp()
         self.utils = baseutils.BaseUtils()
         self.utils._conn = mock.MagicMock()
-        mock.patch.object(imp, 'load_source').start()
+        mock.patch.object(importlib, 'util').start()
 
     @mock.patch.object(baseutils, 'wmi', create=True)
     def test_get_wmi_obj(self, mock_wmi):
@@ -84,7 +84,7 @@ class BaseUtilsVirtTestCase(test_base.OsWinBaseTestCase):
         self.utils = baseutils.BaseUtilsVirt()
         self.utils._conn_attr = mock.MagicMock()
         baseutils.BaseUtilsVirt._os_version = None
-        mock.patch.object(imp, 'load_source').start()
+        mock.patch.object(importlib, 'util').start()
 
     @mock.patch.object(baseutils.BaseUtilsVirt, '_get_wmi_conn')
     def test_conn(self, mock_get_wmi_conn):
@@ -110,13 +110,19 @@ class BaseUtilsVirtTestCase(test_base.OsWinBaseTestCase):
             mock_os]
         fake_module_path = '/fake/path/to/module'
         mock_wmi.__path__ = [fake_module_path]
-        old_conn = imp.load_source.return_value.WMI.return_value
+
+        spec = importlib.util.spec_from_file_location.return_value
+        module = importlib.util.module_from_spec.return_value
+        old_conn = module.WMI.return_value
 
         expected = old_conn.Msvm_VirtualSystemManagementService()[0]
         self.assertEqual(expected, self.utils._vs_man_svc)
         self.assertIsNone(self.utils._vs_man_svc_attr)
-        imp.load_source.assert_called_once_with(
+        importlib.util.spec_from_file_location.assert_called_once_with(
             'old_wmi', '%s.py' % fake_module_path)
+        spec.loader.exec_module.assert_called_once_with(module)
+        importlib.util.module_from_spec.assert_called_once_with(
+            importlib.util.spec_from_file_location.return_value)
 
     @mock.patch.object(baseutils.BaseUtilsVirt, '_get_wmi_compat_conn')
     def test_get_wmi_obj_compatibility_6_3(self, mock_get_wmi_compat):

os_win/utils/baseutils.py

@@ -18,7 +18,7 @@
 Base WMI utility class.
 """
 
-import imp
+import importlib
 import sys
 import threading
 import time
@@ -108,7 +108,11 @@ class BaseUtilsVirt(BaseUtils):
         # .GetText_ have different results.
         if not BaseUtilsVirt._old_wmi:
             old_wmi_path = "%s.py" % wmi.__path__[0]
-            BaseUtilsVirt._old_wmi = imp.load_source('old_wmi', old_wmi_path)
+            spec = importlib.util.spec_from_file_location('old_wmi',
+                                                          old_wmi_path)
+            module = importlib.util.module_from_spec(spec)
+            spec.loader.exec_module(module)
+            BaseUtilsVirt._old_wmi = module
         return BaseUtilsVirt._old_wmi.WMI(moniker=moniker, **kwargs)
 
     def _get_wmi_obj(self, moniker, compatibility_mode=False, **kwargs):