Instructions telling sudo pip install are inherently wrong.
If there is any tutorial out there which says you should do sudo pip then please file a bug against this package. The author is dis-educating Python community, as time has proven sudo pip to be a broken practice.
OSX El Capitan introduced a mechanisms to prevent damaging the operating system files. /System/Library/Frameworks/Python.framework/Versions/2.7/share is one of the protected locations. A normal user has no reason to put or write any files there. This is because the operating system itself relies on these files and sudo pip, with all force given from the above, would unconditionally overwrite them. Usually bad things would not happen, but the chances are there. Apple wants to protect their OS users to accidentally bricking their installation.
Instead, you need to install a Python package, like IPython, locally to the home folder of your user. The easiest way is to create a virtual environment, activate it and then run pip in the virtual environment.
Example:
cd ~ # Go to home directory
virtualenv my-venv
source my-venv/bin/activate
pip install IPython
More info
Alternatively, one should be able to do pip install --user. But again, no sudo needed and you need to manually set up PATH environment variable.