Malfunction in getting a peak for DistributionNotFound

I recently coded with Python a small program with a simple GUI (Tkinter). Now I need PIL to use images. I want to install PIL using PIP, but. After installing PIP, it always gives me this output:

Traceback (most recent call last):
  File "/usr/local/bin/pip", line 5, in <module>
    from pkg_resources import load_entry_point
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 2872, in <module>


  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 451, in _build_master
    def _build_from_requirements(cls, req_spec):
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 464, in _build_from_requirements
    for entry in sys.path:
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 639, in resolve
    fallback=True):
pkg_resources.DistributionNotFound: pip==1.5.6

      

        
        
        
      

    

Does anyone know what's going on here? I am using Elementary OS Freya (Ubuntu 14.04)