Python 3: Fix basestring, long and StringIO

* The basestring type was removed in Python 3: replace it with
  six.string_types.
* Replace StringIO.StringIO with six.StringIO
* Replace (int, long) with six.integer_types

Change-Id: Ic0d443b0bdd00fb18452e79ffae07b9be0fa8116

swift/common/middleware/slo.py

@@ -297,11 +297,11 @@ def parse_and_validate_input(req_body, req_path):
                              for ek in sorted(extraneous_keys))))
             continue
 
-        if not isinstance(seg_dict['path'], basestring):
+        if not isinstance(seg_dict['path'], six.string_types):
             errors.append("Index %d: \"path\" must be a string" % seg_index)
             continue
         if not (seg_dict['etag'] is None or
-                isinstance(seg_dict['etag'], basestring)):
+                isinstance(seg_dict['etag'], six.string_types)):
             errors.append(
                 "Index %d: \"etag\" must be a string or null" % seg_index)
             continue

swift/common/swob.py

@@ -284,7 +284,7 @@ def _resp_status_property():
         return '%s %s' % (self.status_int, self.title)
 
     def setter(self, value):
-        if isinstance(value, (int, long)):
+        if isinstance(value, six.integer_types):
             self.status_int = value
             self.explanation = self.title = RESPONSE_REASONS[value][0]
         else:

swift/common/utils.py

@@ -964,7 +964,7 @@ def decode_timestamps(encoded, explicit=False):
     # TODO: some tests, e.g. in test_replicator, put float timestamps values
     # into container db's, hence this defensive check, but in real world
     # this may never happen.
-    if not isinstance(encoded, basestring):
+    if not isinstance(encoded, six.string_types):
         ts = Timestamp(encoded)
         return ts, ts, ts
 

test/unit/cli/test_ring_builder_analyzer.py

@@ -17,8 +17,8 @@
 import os
 import json
 import mock
+from six import StringIO
 import unittest
-from StringIO import StringIO
 from test.unit import with_tempdir
 
 from swift.cli.ring_builder_analyzer import parse_scenario, run_scenario