Gfilui

Try install it with easy_install:

easy_install -U pip

I had the same issue for a long time and figured out the solution today. When you install pip via python-pip, you download from the deprecated Linux server. You should download from the python server. To solve this, do the following:

sudo apt-get purge pip
sudo apt-get python-setuptools
sudo apt-get python-dev 
sudo easy_install pip 
pip install pip --upgrade 

Actually, you can edit your 'pip' script:

from root:

$ which pip # -> prints 'pip' location

$ nano `which pip` # -> open with your editor, note the backticks!

replace the __requires__ with your latests pip version like:

__requires__ = 'pip==7.1.2'

than edit line with 'load_entry_point' call to:

load_entry_point(__requires__, 'console_scripts', 'pip')()

and:

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

also, i have to update my setuptools package, to install some packages.

This is caused by a conflict between a version of pip provided by a system package, like python-pip, and a version provided by PyPI through pip itself.

To fix this, simply remove python-pip with sudo apt-get purge python-pip.

If you had already used the old version of pip to install a newer version, this should leave the updated version in /usr/local/bin. If not, you can install the most recent version of Pip from scratch with:

curl --silent --show-error --retry 5 https://bootstrap.pypa.io/get-pip.py | sudo python2.7

Use this link to upgrade. Basically:

1. Download the file get-pip.py
   


2. run python get-pip.py
   

Try running sudo -H pip3 install --upgrade pip to upgrade your pip3 (for Python 3).
Conversely, you can do sudo -H pip2 install --upgrade pip to upgrade pip as well (for Python 2).

If python-pip installed from apt repositories with sudo user - run sudo -H install --upgrade pip , same for installing PIP modules .

Here the output from my console on 16.04

..... Successfully installed requests
You are using pip version 8.1.1, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
:~$ pip install --upgrade pip
Collecting pip
 Downloading pip-9.0.1-py2.py3-none-any.whl (1.3MB)
 100% |████████████████████████████████| 1.3MB 672kB/s 
Installing collected packages: pip
Successfully installed pip-8.1.1
You are using pip version 8.1.1, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
:~$ sudo -H pip install --upgrade pip
Collecting pip
 Downloading pip-9.0.1-py2.py3-none-any.whl (1.3MB)
 100% |████████████████████████████████| 1.3MB 692kB/s 
Installing collected packages: pip
 Found existing installation: pip 8.1.1
 Not uninstalling pip at /usr/lib/python2.7/dist-packages, outside environment /usr
Successfully installed pip-9.0.1
:~$ 

also see What is the -H flag for pip? https://stackoverflow.com/questions/28619686/what-is-the-h-flag-for-pip

I'm only a beginner so I'm not sure but probably is something related to the differences between python 2 and 3. I think that is not necessary to be a superuser but you can do it easily using pip3 instead of pip also to upgrade pip :
pip3 install --upgrade pip

I ran into this problem when working on a remote machine I was ssh'd into. I had just installed python 3, and was unable to get pip to upgrade, even though I'd attempted to upgrade via both pip AND apt-get.

Logging out of the remote server and logging back in fixed it.