install python 3.7 mac and link code example
Example: mac why is python installed in usr and application
$ pyenv global 3.7.3
# and verify it worked
$ pyenv version
3.7.3 (set by /Users/mbbroberg/.pyenv/version)
$ pyenv global 3.7.3
# and verify it worked
$ pyenv version
3.7.3 (set by /Users/mbbroberg/.pyenv/version)