test: use rb' instead of b' with \

Author: gpshead

Lib/test/test_cmd_line.py

@@ -65,7 +65,7 @@ def test_help_env(self):
     def test_help_xoptions(self):
         out = self.verify_valid_flag('--help-xoptions')
         self.assertIn(b'-X dev', out)
-        options = re.findall(b'^-X (\\w+)', out, re.MULTILINE)
+        options = re.findall(rb'^-X (\w+)', out, re.MULTILINE)
         self.assertEqual(options, sorted(options),
                          "options should be sorted alphabetically")