How to completely replace python 3 with python 2 in arch linux

Question

I want to completely replace python 3 with python 2 in arch linux. I have already read https://wiki.archlinux.org/index.php/Python but it only provides a temporary fix. I need to ensure that when I call

#!/usr/bin/python

My program is using python 2 instead of python 3.

Answer 1

In Arch, /usr/bin/python is actually a symlink to python3. Assuming you've already installed python2, as root, change the symlink to point to python2:

cd /usr/bin
ls -l python
    lrwxrwxrwx 1 root root 7  5 sept. 07:04 python -> python3
ln -sf python2 python
ls -l python
    lrwxrwxrwx 1 root root 7 Dec 11 19:28 python -> python2

If you're using the python2-virtualenv package, then do the same for /usr/bin/virtualenv:

cd /usr/bin
ln -sf virtualenv2 virtualenv

Answer 2

Changing the default symlink is a bad idea, and it gets recreated on python3 updates. Instead, create a local python override:

sudoedit /usr/local/bin/python

Paste this inside and save the file:

#!/bin/bash
exec python2 "$@"

Don't forget to make it executable:

sudo chmod +x /usr/local/bin/python