1. 安裝Python軟件工具
sudo apt-get install python-software-properties
2. 添加倉庫鏡像源
sudo add-apt-repository ppa:fkrull/deadsnakes
或
sudo vim /etc/apt/sources.list.d/fkrull-ubuntu-deadsnakes-xenial.list
添加源：deb http://ppa.launchpad.net/fkrull/deadsnakes/ubuntu xenial main
3. 更新源
sudo apt-get update
4. 從本地倉庫安裝python
sudo apt-get install python3.6