Update tests

Author: XuehaiPan

Lib/test/test_sys.py

@@ -719,6 +719,8 @@ def test_attributes(self):
         self.assertIn(sys.float_repr_style, ('short', 'legacy'))
         if not sys.platform.startswith('win'):
             self.assertIsInstance(sys.abiflags, str)
+        else:
+            self.assertFalse(hasattr(sys, 'abiflags'))
 
     def test_thread_info(self):
         info = sys.thread_info

Lib/test/test_sysconfig.py

@@ -615,13 +615,17 @@ def test_abiflags(self):
         abiflags = sysconfig.get_config_var('abiflags')
         ABIFLAGS = sysconfig.get_config_var('ABIFLAGS')
 
+        self.assertIsInstance(abiflags, str)
+        self.assertIsInstance(ABIFLAGS, str)
         self.assertIn(abiflags, ABIFLAGS)
+        if ABIFLAGS:
+            self.assertTrue(ABIFLAGS.isalpha(), ABIFLAGS)
 
         if os.name == 'nt':
             self.assertEqual(abiflags, '')
 
         if support.Py_DEBUG:
-            self.assertIn('d', ABIFLAGS)
+            self.assertEndsWith(ABIFLAGS, 'd')
         else:
             self.assertNotIn('d', ABIFLAGS)
         if support.Py_GIL_DISABLED: