How to run pip of different version of python using python command?

I'm now currently using Python on ubuntu 15.10

But in my OS, I have many different python version installed:

• Python (2.7.9)
• Python3 (3.4.3)
• Python3.5
• PyPy

So, I got mess about the version of their package environment, for example, if I run:

pip3 install django

In fact I cannot import django inside python3.5.

Is there any efficiently way to call the relating version of pip?

PS: Don't suggest that I use virtualenv, I know about it and am seeking another solution.

Finally I found the solution myself, see the Docs:

https://docs.python.org/3/installing/index.html?highlight=pip#work-with-multiple-versions-of-python-installed-in-parallel

Just call:

pythonXX -m pip install SomePackage

That would work separately for each version of installed python.

Also, according to the docs, if we want to do the same thing in windows, the command is a bit different:

py -2   -m pip install SomePackage  # default Python 2
py -2.7 -m pip install SomePackage  # specifically Python 2.7
py -3   -m pip install SomePackage  # default Python 3
py -3.4 -m pip install SomePackage  # specifically Python 3.4

How about using pyenv?

You can switch the version.

$ pyenv install 2.7.X
$ pyenv install 3.5.X
$ pyenv local 2.7.X
$ pyenv global 3.5.X

This solution worked for me:

sudo python2.7 -m pip install [package name]