explicitly close files
diff --git a/Lib/test/test_difflib.py b/Lib/test/test_difflib.py
index 83fad15..011ef17 100644
--- a/Lib/test/test_difflib.py
+++ b/Lib/test/test_difflib.py
@@ -135,14 +135,13 @@
              k.make_table(f3.splitlines(True),t3.splitlines(True)),
              ])
         actual = full.replace('</body>','\n%s\n</body>' % tables)
-        # temporarily uncomment next three lines to baseline this test
-        #f = open('test_difflib_expect.html','w')
-        #f.write(actual)
-        #f.close()
-        expect = open(findfile('test_difflib_expect.html')).read()
 
+        # temporarily uncomment next two lines to baseline this test
+        #with open('test_difflib_expect.html','w') as fp:
+        #    fp.write(actual)
 
-        self.assertEqual(actual,expect)
+        with open(findfile('test_difflib_expect.html')) as fp:
+            self.assertEqual(actual, fp.read())
 
     def test_recursion_limit(self):
         # Check if the problem described in patch #1413711 exists.