Use different Python version with virtualenv

Just use the --python (or short -p) option when creating your virtualenv instance to specify the Python executable you want to use, e.g.:

virtualenv --python=/usr/bin/python2.6 <path/to/new/virtualenv/>

N.B. For Python 3.3 or later, refer to The Aelfinns answer below.

Since Python 3, the Python Docs suggest creating the virtual environment with the following command:

python3 -m venv <myenvname>

Please note that venv does not permit creating virtual environments with other versions of Python. For that, install and use the virtualenv package.

Obsolete information

The pyvenv script can be used to create a virtual environment

pyvenv /path/to/new/virtual/environment

but it has been deprecated since Python 3.6.

Use different Python version with virtualenv

These are the steps you can follow when you are on a shared hosting environment and need to install & compile Python from source and then create venv from your Python version. For Python 2.7.9. you would do something along these lines:

mkdir ~/src
wget http://www.python.org/ftp/python/2.7.9/Python-2.7.9.tgz
tar -zxvf Python-2.7.9.tgz
cd Python-2.7.9
mkdir ~/.localpython
./configure --prefix=$HOME/.localpython
make
make install

virtual env

cd ~/src
wget https://pypi.python.org/packages/5c/79/5dae7494b9f5ed061cff9a8ab8d6e1f02db352f3facf907d9eb614fb80e9/virtualenv-15.0.2.tar.gz#md5=0ed59863994daf1292827ffdbba80a63
tar -zxvf virtualenv-15.0.2.tar.gz
cd virtualenv-15.0.2/
~/.localpython/bin/python setup.py install
virtualenv ve -p $HOME/.localpython/bin/python2.7
source ve/bin/activate

Naturally, this can be applicable to any situation where you want to replicate the exact environment you work and deploy on.