How to change the Python Default version

At times you may want to change the version of Python to a specific version instead of the default of your system. In such case you can try making aliases.

First let's try to get the list of all Python versions installed on the device.

# ls -ltrh /usr/bin/python*

-rwxr-xr-x  2 root  wheel    21K Feb 10  2023 /usr/bin/python
-rwxr-xr-x  5 root  wheel   3.4M Feb 10  2023 /usr/bin/python2.7
-rwxr-xr-x  5 root  wheel   3.4M Feb 10  2023 /usr/bin/python2.7-config
lrwxr-xr-x  1 root  wheel    75B Feb 10  2023 /usr/bin/python2 -> ../../System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7
-rwxr-xr-x  3 root  wheel    23K Feb 10  2023 /usr/bin/python3
lrwxr-xr-x  1 root  wheel    76B Feb 10  2023 /usr/bin/python3.7 -> ../../System/Library/Frameworks/Python.framework/Versions/3.7/bin/python3.7
-rwxr-xr-x  6 root  wheel   3.5M Jun  3  2023 /usr/bin/python3.8
lrwxr-xr-x  1 root  wheel    76B Jun  3  2023 /usr/bin/python3.8-config -> ../../System/Library/Frameworks/Python.framework/Versions/3.8/bin/python3.8-config
-rwxr-xr-x  6 root  wheel   3.5M Jun  3  2023 /usr/bin/python3.8-config
lrwxr-xr-x  1 root  wheel    79B Jun  3  2023 /usr/bin/python3.8-config -> ../../System/Library/Frameworks/Python.framework/Versions/3.8/bin/python3.8-config
-rwxr-xr-x  6 root  wheel   3.5M Jun  3  2023 /usr/bin/python3.8

Let's say I want Python 3.7 to be the default one and others can be aliased to python38 and python27

alias python='/usr/bin/python3.7'
alias python38='/usr/bin/python3.8'
alias python2='/usr/bin/python2.7'

based on your preferences, save this in .zshrc or .bash_profile and reload the shell.

# python --version

Python 3.8