ImportError: No module named skimage.io

[Georgios Samaras]

I am trying to do this:

sudo pip install -U scikit-image

but I am getting:

Cleaning up...
Exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 122, in 
main
    status = self.run(options, args)
  File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 
278, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, 
bundle=self.bundle)
  File "/usr/lib/python2.7/dist-packages/pip/req.py", line 1091, in 
prepare_files
    req_to_install.check_if_exists()
  File "/usr/lib/python2.7/dist-packages/pip/req.py", line 811, in 
check_if_exists
    self.satisfied_by = pkg_resources.get_distribution(self.req)
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", 
line 535, in get_distribution
    dist = get_provider(dist)
  File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", 
line 415, in get_provider
    return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
IndexError: list index out of range

Storing debug log for failure in /home/gsamaras/.pip/pip.log
--------------------------------------------------------------------------------------------------------------------------------------------------------

How to fix this? For more, see this SO question 
<https://stackoverflow.com/questions/37623259/unable-to-import-caffe>.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/scikit-image/attachments/20160603/ac2ff33d/attachment.html>