Cannot install python six module

I have a server in the AWS cloud. It was running a flask API which calls the Google STT API fine. I then attempted to 'productionise' the API by setting up a virtualenv and getting the API to run there, with the intent of running Gunicorn.

When I tried to run the API in the virtual container it gave an error about importing the google api client. There was no google api client folder in my virtualenv so I copied folders across from the main python2.7 site-packages folder. Then I got an error saying it could not import six in googleapiclient/discovery.py. The error was "ImportError: No module named six".

There was no six directory in my virtualenv python folder. So I tried to copy across a folder named six-1.10.0.dist-info from my main python2.7 folder but that didnt help. I tried many things...such as forcing a reinstall but still the same error with the google api reference from googleapiclient/discovery.py. So I tried "sudo pip uninstall six; sudo pip install six". This successfully uninstalled, but now I cannot install again. When I run "sudo pip install six" I get the following:

Traceback (most recent call last):
  File "/usr/bin/pip", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 48, in <module>
import six
ImportError: No module named six

I have also tried easy_install and options like --upgrade --ignore-installed but with no change in the behaviour.

What the heck is going on? Why cant I reinstall six? Why would it not be recognised anyway?

UPDATE So this post stackoverflow.com/questions/13270877/… helped me to install six back into the main python environment. My API runs fine there now. But the same approach has not worked for the virtual environment.

Running "unset PYTHONPATH" seems to have helped me install modules into the virtualenv. The AWS image seems to have come with a python path already added that was confusing virtualenv. However I am still getting the nonsense below with six. What is going on?

(myprojectenv)[ec2-user@ip-172-31-29-83 myapi]$ python api.py
Traceback (most recent call last):
  File "api.py", line 3, in <module>
    from googleapiclient import discovery
  File "/home/ec2-user/myapi/myprojectenv/local/lib/python2.7/site-packages/googleapiclient/discovery.py", line 20, in <module>
import six
ImportError: No module named six
(myprojectenv)[ec2-user@ip-172-31-29-83 myapi]$ pip install --upgrade six
Requirement already up-to-date: six in ./myprojectenv/lib/python2.7/site-packages