update-alternatives --query python
update-alternatives: error: no alternatives for python
sudo update-alternatives --install /usr/local/bin/python python `which python3.8` 2
# update-alternatives: using /usr/bin/python3.8 to provide /usr/local/bin/python (python) in auto mode
sudo update-alternatives --install /usr/local/bin/python python `which python2.7` 5
# update-alternatives: using /usr/bin/python2.7 to provide /usr/local/bin/python (python) in auto mode
update-alternatives --query python
# Name: python
# Link: /usr/local/bin/python
# Status: auto
# Best: /usr/bin/python2.7
# Value: /usr/bin/python2.7
#
# Alternative: /usr/bin/python2.7
# Priority: 5
#
# Alternative: /usr/bin/python3.8
# Priority: 2
sudo update-alternatives --install /usr/local/bin/python python `which python3.8` 20
# update-alternatives: using /usr/bin/python3.8 to provide /usr/local/bin/python (python) in auto mode
