Mac Python3.7.3切換3.6.5_1

$ brew unlink python

安裝3.6.5
$ brew install --ignore-dependencies https://raw.githubusercontent.com/Homebrew/homebrew-core/f2a764ef944b1080be64bd88dca9a1d80130c558/Formula/python.rb

$ brew switch python 3.7.3

$ brew switch python 3.6.5_1



參考
https://stackoverflow.com/questions/51726203/installing-python3-6-alongside-python3-7-on-mac