Fallback to StringIO if cStringIO doesn't exist.

bson/py3compat.py

@@ -20,6 +20,9 @@
 
 if PY3:
     import codecs
+
+    from  io import BytesIO as StringIO
+
     def b(s):
         # BSON and socket operations deal in binary data. In
         # python 3 that means instances of `bytes`. In python
@@ -37,6 +40,11 @@ def bytes_from_hex(h):
     text_type   = str
 
 else:
+    try:
+        from cStringIO import StringIO
+    except ImportError:
+        from StringIO import StringIO
+
     def b(s):
         # See comments above. In python 2.x b('foo') is just 'foo'.
         return s

gridfs/grid_file.py

@@ -17,18 +17,10 @@
 import datetime
 import math
 import os
-import sys
-
-if sys.version_info[0] == 3:
-    from io import BytesIO as StringIO
-else:
-    # 2to3 will turn cStringIO into io. That's okay
-    # since we'll never get here under python3.
-    from cStringIO import StringIO
 
 from bson.binary import Binary
 from bson.objectid import ObjectId
-from bson.py3compat import b, binary_type, string_types, text_type
+from bson.py3compat import b, binary_type, string_types, text_type, StringIO
 from gridfs.errors import (CorruptGridFile,
                            FileExists,
                            NoFile,

test/test_grid_file.py

@@ -17,10 +17,6 @@
 """Tests for the grid_file module.
 """
 
-try:
-    from io import BytesIO as StringIO
-except ImportError:
-    from cStringIO import StringIO
 import datetime
 import os
 import sys
@@ -30,7 +26,7 @@
 from nose.plugins.skip import SkipTest
 
 from bson.objectid import ObjectId
-from bson.py3compat import b
+from bson.py3compat import b, StringIO
 from gridfs.grid_file import (DEFAULT_CHUNK_SIZE,
                               _SEEK_CUR,
                               _SEEK_END,

test/test_gridfs.py

@@ -22,10 +22,6 @@
 from pymongo.read_preferences import ReadPreference
 from test.test_replica_set_connection import TestConnectionReplicaSetBase
 
-try:
-    from io import BytesIO as StringIO
-except ImportError:
-    from cStringIO import StringIO
 import datetime
 import unittest
 import threading
@@ -35,7 +31,7 @@
 
 import gridfs
 
-from bson.py3compat import b
+from bson.py3compat import b, StringIO
 from gridfs.errors import (FileExists,
                            NoFile)
 from test.test_connection import get_connection