python3 update in MacOS

1. install python3 from brew:

brew install python3

the installed path is /usr/local/bin/python3 as well as the pip3.

2. config the enviroment in shell.

pip

echo "alias pip=/usr/local/bin/pip3" >> ~/.zshrc 
# or for Bash
echo "alias pip=/usr/local/bin/pip3" >> ~/.bashrc

python:

echo "alias python3=/usr/local/bin/python3" >> ~/.zshrc