Changing default python to another version

Question

Currently when I use \"python\" command, it points to python2.6. I have installed python3.1 and I want the \"python\" command point to python3.1. How it is possible?

Answer 1

It is not advisable.

You could write at the top in your own script (a shebang):

#!/usr/bin/env python3

If you're on Windows then install pylauncher. It understands #!.

On Linux to make your script executable, run once:

$ chmod +x your-script

After that, to run your script:

$ ./your-script

For interactive use you could create virtualenv as @Petr Viktorin points out. To install/upgrade (versions from Ubuntu's repositries are too old):

$ pip install -U virtualenv{,wrapper}

Follow instructions in /path/to/virtualenvwrapper.sh, to create virtualenv that uses python3:

$ mkvirtualenv --python python3 py3

To activate virtualenv:

$ workon py3

In an active virtualenv python refers to /path/virtualenv/bin/python. So you could run:

$ python your_module.py