Use different Python version with virtualenv

Question

I have a Debian system currently running with python 2.5.4. I got virtualenv properly installed, everything is working fine. Is there a possibility that I can use a virtuale

Answer 1

There is an easier way,

virtualenv venv --python=python2.7

Thanks to a comment, this only works if you have python2.7 installed at the system level (e.g. /usr/bin/python2.7).

Otherwise, if you are using homebrew you can use the path to give you what you want.

virtualenv venv --python=/usr/local/bin/python

You can find the path to your python installation with

which python

This will also work with python 3.

which python3
>> /usr/local/bin/python3
virtualenv venv --python=/usr/local/bin/python3

Ultimately condensing to:

virtualenv venv -p `which python`
virtualenv venv -p `which python3`

Answer 2

The -p approach works well, but you do have to remember to use it every time. If your goal is to switch to a newer version of Python generally, that's a pain and can also lead to mistakes.

Your other option is to set an environment variable that does the same thing as -p. Set this via your ~/.bashrc file or wherever you manage environment variables for your login sessions:

export VIRTUALENV_PYTHON=/path/to/desired/version

Then virtualenv will use that any time you don't specify -p on the command line.

Answer 3

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 Aelfinn's answer below.

Answer 4

It worked for me

sudo apt-get install python3-minimal

virtualenv --no-site-packages --distribute -p /usr/bin/python3 ~/.virtualenvs/py3

Answer 5

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.

Answer 6

Under Windows for me this works:

virtualenv --python=c:\Python25\python.exe envname

without the python.exe I got WindowsError: [Error 5] Access is denied I have Python2.7.1 installed with virtualenv 1.6.1, and I wanted python 2.5.2.