title: error while running any python-dependent commands/programs in terminal
body: <p>I recently set up arch on my machine; installed python. <code>/usr/bin/python</code> was symlinked to <code>/usr/bin/python3</code> which itself is a symlink to <code>/usr/bin/python3.4</code>.<br>
  Because, I use python2.7, I went ahead and linked <code>python</code> to <code>python2.7</code>.<br>
  Now when I try to python dependent program, I get the following error.  </p>
  
  <pre><code>Traceback (most recent call last):
  File "/usr/bin/pip", line 5, in &lt;module&gt;
  from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3084, in &lt;module&gt;
  @_call_aside
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3070, in _call_aside
  f(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3097, in _initialize_master_working_set
  working_set = WorkingSet._build_master()
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 651, in _build_master
  ws.require(__requires__)
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 952, in require
  needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 839, in resolve
  raise DistributionNotFound(req, requirers)
  pkg_resources.DistributionNotFound: The 'pip==7.1.2' distribution was not found and is required by the application
  </code></pre>
  
  <p>I wish to know what's gone wrong.</p>