error while running any python-dependent commands/programs in terminal
Question: I recently set up arch on my machine; installed python. `/usr/bin/python` was
symlinked to `/usr/bin/python3` which itself is a symlink to
`/usr/bin/python3.4`.  
Because, I use python2.7, I went ahead and linked `python` to `python2.7`.  
Now when I try to python dependent program, I get the following error.

    
    
    Traceback (most recent call last):
    File "/usr/bin/pip", line 5, in <module>
    from pkg_resources import load_entry_point
    File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3084, in <module>
    @_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
    

I wish to know what's gone wrong.


Answer: The `pip` script in `/usr/bin` is tied to Python 3.4. The small script is just
a bootstrapping script to load the actual code from a module. That module is
missing in Python 2.7 because you did not install `pip` for it.

Either fix the script to replace `/usr/bin/python` in the first line with
`/usr/bin/python3`, or [install `pip` for Python
2.7](https://pip.pypa.io/en/stable/installing/).

Alternatively, only link `/usr/bin/python2` to Python 2.7 and leave
`/usr/bin/python` to point to Python 3. It is quite likely other Arch programs
rely on that being Python 3, anyway. Also see ["Proper way" to manage multiple
versions of Python on
archlinux](http://stackoverflow.com/questions/7297094/proper-way-to-manage-
multiple-versions-of-python-on-archlinux).

