Why am I getting command not found even though path to command exists in PATH variable?
The fix I ended up was removing all home brew Python and fixing up the system Python. 

brew remove python
brew remove python3
brew cleanup


Check for the system pip and python (or absence of pip is OK too).

which python
which pip
which pip3
which python3


At this point, you need to easy_install a system based pip:

sudo easy_install --upgrade pip
pip --version


You should now have a pip that's based on /Library/Python (and pip 7.1.2 against python 2.7 for El Capitan in October 2015)

mac:~ me$ pip --version
pip 7.1.2 from /Library/Python/2.7/site-packages/pip-7.1.2-py2.7.egg (python 2.7)
mac:~ me$ which pip
/usr/local/bin/pip
mac:~ me$ which python
/usr/bin/python