title: cannot install python using brew
body: <p>Trying to install python using the following command:</p>
  
  <p><code>brew install python</code></p>
  
  <p>But unfortunately I am getting the following error:</p>
  
  <pre><code>&gt;brew install python
  ==&gt; Downloading https://homebrew.bintray.com/bottles/python-2.7.12_2.el_capitan.
  Already downloaded: /Users/maguerra/Library/Caches/Homebrew/python-2.7.12_2.el_capitan.bottle.tar.gz
  ==&gt; Pouring python-2.7.12_2.el_capitan.bottle.tar.gz
  ==&gt; Using the sandbox
  ==&gt; /usr/local/Cellar/python/2.7.12_2/bin/python -s setup.py --no-user-cfg insta
  Last 15 lines from /Users/maguerra/Library/Logs/Homebrew/python/post_install.01.python:
  copying setuptools/command/rotate.py -&gt; build/lib/setuptools/command
  copying setuptools/command/saveopts.py -&gt; build/lib/setuptools/command
  copying setuptools/command/sdist.py -&gt; build/lib/setuptools/command
  copying setuptools/command/setopt.py -&gt; build/lib/setuptools/command
  copying setuptools/command/test.py -&gt; build/lib/setuptools/command
  copying setuptools/command/upload.py -&gt; build/lib/setuptools/command
  copying setuptools/command/upload_docs.py -&gt; build/lib/setuptools/command
  creating build/lib/setuptools/extern
  copying setuptools/extern/__init__.py -&gt; build/lib/setuptools/extern
  copying setuptools/script (dev).tmpl -&gt; build/lib/setuptools
  copying setuptools/script.tmpl -&gt; build/lib/setuptools
  running install_lib
  copying build/lib/easy_install.py -&gt; /usr/local/lib/python2.7/site-packages
  copying build/lib/pkg_resources/__init__.py -&gt; /usr/local/lib/python2.7/site-packages/pkg_resources
  error: [Errno 13] Permission denied: '/usr/local/lib/python2.7/site-  packages/pkg_resources/__init__.py'
  Warning: The post-install step did not complete successfully
  You can try again using `brew postinstall python`
  
  ==&gt; Caveats
  Pip and setuptools have been installed. To update them 
    pip install --upgrade pip setuptools
  
  You can install Python packages with
    pip install &lt;package&gt;
  
  They will install into the site-package directory
    /usr/local/lib/python2.7/site-packages
  
  See: https://github.com/Homebrew/brew/blob/master/docs/Homebrew-and Python.md
  
  .app bundles were installed.
  Run `brew linkapps python` to symlink these to /Applications.
  ==&gt; Summary
    /usr/local/Cellar/python/2.7.12_2: 3,150 files, 42.5M
  </code></pre>
  
  <p>Has anyone seen this before, or now how to address this issue in order to complete the python installation process? </p>