Minor refactoring of the variable names

tests/test_http.py

Index: tests/test_http.py
diff --git a/tests/test_http.py b/tests/test_http.py
index 391e13d942a0646b9700adafaad8a89c5dd51117..43569ed234528043cd91ab951f5b254449212615 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -634,23 +634,23 @@ class TestHttpRequest(unittest.TestCase):
     self.assertEqual({u'foo': u'bar'}, response)
 
   def test_retry_ssl_errors_resumable(self):
-    f = open(datafile('small.png'), 'rb')
-    fd = BytesIO(f.read())
-    upload = MediaIoBaseUpload(
-        fd=fd, mimetype='image/png', chunksize=500, resumable=True)
-    model = JsonModel()
-
-    request = HttpRequest(
-        HttpMockWithSSLErrors(
-            3, {'status': '200', 'location': 'location'}, '{"foo": "bar"}'),
-        model.response,
-        u'https://www.example.com/file_upload',
-        method='POST',
-        resumable=upload)
-    request._sleep = lambda _x: 0  # do nothing
-    request._rand = lambda: 10
-    response = request.execute(num_retries=3)
-    self.assertEqual({u'foo': u'bar'}, response)
+    with open(datafile('small.png'), 'rb') as small_png_file:
+      small_png_file_descriptor = BytesIO(small_png_file.read())
+      upload = MediaIoBaseUpload(fd=small_png_file, mimetype='image/png',
+                                 chunksize=500, resumable=True)
+      model = JsonModel()
+
+      request = HttpRequest(
+          HttpMockWithSSLErrors(
+              3, {'status': '200', 'location': 'location'}, '{"foo": "bar"}'),
+          model.response,
+          u'https://www.example.com/file_upload',
+          method='POST',
+          resumable=upload)
+      request._sleep = lambda _x: 0  # do nothing
+      request._rand = lambda: 10
+      response = request.execute(num_retries=3)
+      self.assertEqual({u'foo': u'bar'}, response)
 
   def test_retry(self):
     num_retries = 5