Mac OS
DMG 安装
brew
https://stackoverflow.com/questions/51125013/how-can-i-install-a-previous-version-of-python-3-in-macos-using-homebrew
brew install python3 #安装最新版本python3 == python3.7.0
brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/f2a764ef944b1080be64bd88dca9a1d80130c558/Formula/python.rb # python3.6.5
python3 -V
pip (可省略，brew自动安装)
$ curl -O https://bootstrap.pypa.io/get-pip.py
$ sudo python3 get-pip.py
pip3 --version (pip -V)venv
python3 -m venv ENV36
source ENV36/bin/activate
Centos 7
Step1 add the repository
sudo yum install -y https://centos7.iuscommunity.org/ius-release.rpm
sudo yum update
Download and install Python & Pip3
sudo yum install -y python36u python36u-libs python36u-devel python36u-pip
python3.6 -V
创建venv (python 3 内置）
python3 -m venv ENV36
source ENV36/bin/activate