how to set python3 as default python code example

Example 1: 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 2: how to set default python version in macos

ln -s -f /usr/local/bin/python3.7 /usr/local/bin/python