failed in "sudo pip"
Try this:
sudo easy_install --upgrade pip
By executing this you are upgrading the version of pip that sudoer is using.
Please help me.

server : aws ec2
os : amazon linux
python version : 2.7.10


$ pip --version
pip 7.1.2 from /usr/local/lib/python2.7/site-packages (python 2.7)

It's OK.
But...

$ sudo pip --version
Traceback (most recent call last):
  File "/usr/bin/pip", line 5, in 
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 3020, in 
    working_set = WorkingSet._build_master()
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 616, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 629, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 807, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: pip==6.1.1