Cannot import module in pip freeze list
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I cannot import a module that I see in the pip freeze list (in my case django-olwidget, but I don't think it's nothing to do with this module). 

With the virtual environment activated, I:

- uninstalled an old version of the module (0.47) 
- confirmed that it is gone from the freeze list
- pip installed the module again
- checked the module is in the freeze list now (django-olwidget==0.50)

The environment is active but, now I cannot import the module. Any ideas?