Installing matplotlib under Mountain Lion
Follow this steps in order: [carpincho@MacBook-2]$ pip install numpy [carpincho@MacBook-2]$ pip install -e git+https://github.com/scipy/scipy#egg=scipy-dev [carpincho@MacBook-2]$ pip install git+https://github.com/matplotlib/matplotlib.git#egg=matplotlib-dev source and a link to an explanation why numpy and matplotlib can't be installed using pip straightforward