How to fix ImportError: No module named packages.urllib3?

I'm running Python 2.7.6 on an Ubuntu machine. When I run twill-sh (Twill is a browser used for testing websites) in my Terminal, I'm getting the following:

Traceback (most recent call last):
  File "dep.py", line 2, in <module>
    import twill.commands
  File "/usr/local/lib/python2.7/dist-packages/twill/__init__.py", line 52, in <module>
    from shell import TwillCommandLoop
  File "/usr/local/lib/python2.7/dist-packages/twill/shell.py", line 9, in <module>
    from twill import commands, parse, __version__
  File "/usr/local/lib/python2.7/dist-packages/twill/commands.py", line 75, in <module>
    browser = TwillBrowser()
  File "/usr/local/lib/python2.7/dist-packages/twill/browser.py", line 31, in __init__
    from requests.packages.urllib3 import connectionpool as cpl
ImportError: No module named packages.urllib3

However, I can import urllib in Python console just fine. What could be the reason?

There is a difference between the standard urllib and urllib2 and the third-party urllib3.

It looks like twill does not install the dependencies so you have to do it yourself. Twill depends on requests library which comes with and uses urllib3 behind the scenes. You also need lxml and cssselect libraries.

You can install them on terminal as follows:

pip install requests

pip install lxml

and

pip install cssselect