How to install older formula using Brew?

Question

Using the case of installing Python 2.7.9 instead of the latest 2.7.10, previously I could simply use brew versions python and see all of the versions of Python

Answer 1

If you want install a specific python version using brew (Home brew).

Example: I am trying to install python 3.7 and current python at this time is python 3.8

brew install python@3.7 -- This will make me install python 3.7

brew install python -- This will make me install python 3.8 which is current version of python while writing this comment.