title: Two python2 in the cmd and cannot use pip2 for any of the version
body: <p>I am using <code>OS X 10.12</code> and I have some troubles with my python installation. Currently I have two python2 installed. One is <code>Python 2.7.10</code> at <code>/Library/Python/2.7</code> and the other is <code>Python 2.7.13</code> at <code>/usr/local/Cellar/python/2.7.13_1</code>. At the moment, all the pips (pip2, pip2.7, pip) direct to <code>Python 2.7.10</code>, and I cannot use <code>pip</code> for <code>Python 2.7.13</code> in the cmd. Even <code>Python 2.7.10</code> has pips, they do not work, for example, when I tried to upgrade <code>numpy</code>, I got error messages like this:</p>
  
  <p><code>Collecting numpy
    Downloading numpy-1.13.1-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (4.6MB)
      100% |████████████████████████████████| 4.6MB 162kB/s 
  Installing collected packages: numpy
    Found existing installation: numpy 1.8.0rc1
      DEPRECATION: Uninstalling a distutils installed project (numpy) has been deprecated and will be removed in a future version. This is due to the fact that uninstalling a distutils project will only partially uninstall the project.
      Uninstalling numpy-1.8.0rc1:
  Exception:
  Traceback (most recent call last):
    File "/Library/Python/2.7/site-packages/pip/basecommand.py", line 215, in main
      status = self.run(options, args)
    File "/Library/Python/2.7/site-packages/pip/commands/install.py", line 342, in run
      prefix=options.prefix_path,
    File "/Library/Python/2.7/site-packages/pip/req/req_set.py", line 778, in install
      requirement.uninstall(auto_confirm=True)
    File "/Library/Python/2.7/site-packages/pip/req/req_install.py", line 754, in uninstall
      paths_to_remove.remove(auto_confirm)
    File "/Library/Python/2.7/site-packages/pip/req/req_uninstall.py", line 115, in remove
      renames(path, new_path)
    File "/Library/Python/2.7/site-packages/pip/utils/__init__.py", line 267, in renames
      shutil.move(old, new)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 302, in move
      copy2(src, real_dst)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 131, in copy2
      copystat(src, dst)
    File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 103, in copystat
      os.chflags(dst, st.st_flags)
  OSError: [Errno 1] Operation not permitted: '/tmp/pip-N61eSI-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/numpy-1.8.0rc1-py2.7.egg-info'
  </code></p>
  
  <p>What I want to do is to make <code>pip</code> in the cmd for <code>Python 2.7.13</code> and make <code>pip2</code> for <code>Python 2.7.10</code>. And I want them both work.</p>