Fix uploading files in Python 2 (#229)

Fix uploading files in Python 2

neptune/internal/storage/datastream.py

@@ -18,6 +18,7 @@
 import os
 import stat
 import tarfile
+import six
 
 from future.builtins import object
 
@@ -32,7 +33,11 @@ def __init__(self, data, start, end):
 
     def get_data(self):
         if isinstance(self.data, str):
-            return io.StringIO(self.data)
+            # pylint: disable=undefined-variable
+            if six.PY3:
+                return io.StringIO(self.data)
+            else:
+                return io.StringIO(unicode(self.data))
         else:
             return io.BytesIO(self.data)
 

tests/neptune/test_project.py

@@ -14,11 +14,11 @@
 # limitations under the License.
 #
 
-import ntpath
 import os.path
 import sys
 import unittest
 from random import randint
+import ntpath
 
 import pandas as pd
 from mock import MagicMock, patch