How to update Python on mac code example

Example 1: upgrade python version mc

brew install python3
brew update && brew upgrade python
alias python=/usr/local/bin/python3

Example 2: mac os install python 3

brew install python3

Example 3: update link python is python 3

$ python --version
Python 2.7.6
$ python3 --version
Python 3.4.3
$ alias python=python3
$ python --version
Python 3.4.3

Example 4: which python mac

$ brew update && brew upgrade python

Example 5: mac catallina python3

$ brew install pyenv

Example 6: command to install python3.6 on mac os

$ brew unlink python