Issue #20557: Use specific asserts in io tests.
diff --git a/Lib/test/test_file.py b/Lib/test/test_file.py
index 4f2c9ef..1fd7910 100644
--- a/Lib/test/test_file.py
+++ b/Lib/test/test_file.py
@@ -88,8 +88,8 @@
     def testErrors(self):
         f = self.f
         self.assertEqual(f.name, TESTFN)
-        self.assertTrue(not f.isatty())
-        self.assertTrue(not f.closed)
+        self.assertFalse(f.isatty())
+        self.assertFalse(f.closed)
 
         if hasattr(f, "readinto"):
             self.assertRaises((IOError, TypeError), f.readinto, "")