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

On the mac I use pyenv and virtualenvwrapper. I had to create a new virtualenv. You need homebrew which I'll assume you've installed if you're on a mac, but just for fun:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"


brew install pyenv
pyenv install 2.7.10
pyenv global 2.7.10
export PATH=/Users/{USERNAME}/.pyenv/versions/2.7.10/bin:$PATH
mkvirtualenv -p ~/.pyenv/versions/2.7.10/bin/python  {virtual_env_name}

I also froze my requirements first so i could simply reinstall in the new virtualenv with:

pip install -r requirements.txt

Answer 2

In windows subsystem for linux:

1. Create environment for python3:

   virtualenv --python=/usr/bin/python3 env
   

2. Activate it:

   source env/bin/activate
   

Answer 3

Yes you just need to install the other version of python, and define the location of your other version of python in your command like :

virtualenv /home/payroll/Documents/env -p /usr/bin/python3

Answer 4

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.

Answer 5

This was a bug with virtualenv. Just upgrading your pip should be the fix.

pip install --upgrade virtualenv

Answer 6

As already mentioned in multiple answers, using virtualenv is a clean solution. However a small pitfall that everyone should be aware of is that if an alias for python is set in bash_aliases like:

python=python3.6

this alias will also be used inside the virtual environment. So in this scenario running python -V inside the virtual env will always output 3.6 regardless of what interpreter is used to create the environment:

virtualenv venv --python=pythonX.X