I have been using Python 2.7 for most of my Python work but have a few projects where I want to use Python 3.x. In these cases I want to create a Virtualenv virtual environment with Python 3.x.
Turns out that is is no problem to have Python 2.7 and Python 3.x installed on the same machine as long as they are installed in their own folders.
You just have to selectively call either when you want to use them but you choose which version you want to have in your Windows path so when you call ‘python’ at command line, you run that version by default. I have Python 2.7 in my Windows environment Path.
So to create a new Python 2.7 virtual environment just call Virtualenv normally:
c:\path\to\my\project>virtualenv venv
To create a new Python 3.x virtual environment just use the ‘-p’ switch and use the Python 3.x path and executable to have Virtualenv create new virtual environment with Python 3.x:
c:\path\to\my\project>virtualenv -p c:\python34\python.exe venv