You can create Python virtualenv using command:
virtualenv -p /usr/bin/python3 py-env3
You may encounter following strange error:
Collecting setuptools Exception: Traceback (most recent call last): File "/usr/share/python-wheels ... OSError: Could not find a suitable TLS CA certificate bundle, invalid path: /etc/ssl/certs/ca-certificates.crt ... Error in sys.excepthook: Traceback (most recent call last): File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 145, in apport_excepthook os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o640), 'wb') as f: FileNotFoundError: [Errno 2] No such file or directory: '/var/crash/_usr_bin_virtualenv.1000.crash'
The error message is not very clear. Problem is caused by ca-certificates and it could be fixed by command:
sudo update-ca-certificates