issues with six under django?

Question

I'm trying to use a package called vcrpy to accelerate the execution of my django application test suite. I'm using django 1.7 on Mac, with Python 2.7.

I added the following couple of lines to one of my tests:

import vcr
with vcr.use_cassette('recording.yaml'):

The result is an import error:

    import vcr
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/vcr/__init__.py", line 2, in <module>
    from .config import VCR
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/vcr/config.py", line 6, in <module>
    from .cassette import Cassette
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/vcr/cassette.py", line 12, in <module>
    from .patch import CassettePatcherBuilder
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/vcr/patch.py", line 8, in <module>
    from .stubs import VCRHTTPConnection, VCRHTTPSConnection
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/vcr/stubs/__init__.py", line 9, in <module>
    from six.moves.http_client import (
ImportError: No module named http_client

The problematic code in the VCR package itself is:

import six
from six.moves.http_client import (
    HTTPConnection,
    HTTPSConnection,
    HTTPMessage,
    HTTPResponse,
)

The funny thing: this code seems to run fine when I'm just running it from a plain python console, but it results in the above ImportError under Django or under the django manage.py shell.

Any idea what might be wrong?

( some additional details about the location of the six module:

When I'm running plain python console, I get the following:

Python 2.7.8 (v2.7.8:ee879c0ffa11, Jun 29 2014, 21:07:35) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 
>>> import six
>>> print six.__file__
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/six.pyc

Doing the same thing, with import django; django.setup(), from manage.py shell results in exactly the same directory and same six.pyc file.

)

Answer 1

Maybe a little bit too late for the original question, but I came here trough Google so for future reference, here's my solution:

Problem

The problem I found is that mac os comes with not only python but also some packages pre-installed. Six is one of those packages and therein lies the conflict. The pre-installed six takes priority over the pip installed six, but pip still gives information based on what it itself has installed (e.g. six 1.9.0 vs 1.4.1).

pre-installed (version 1.4.1):

/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/

pip installed (whatever you have installed, for me it was 1.9.0):

/Library/Python/2.7/site-packages/

You can check if this is the case for you by running:

$ python
>>> import six
>>> print six.__file__
'/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/six.py'

Fixing it

The solution is actually quite simple, just put

export PYTHONPATH="/Library/Python/2.7/site-packages:$PYTHONPATH"

in your ~/.bashrc (or whatever file your shell uses). If you've configured your pip to install somewhere else, put that in the pythonpath instead.