ubuntu1404 install python3.8
下载解压：
wget https://www.python.org/ftp/python/3.8.2/Python-3.8.2.tgz
tar -zxvf Python-3.8.2.tgz
编译
cd Python3.8.2
./configure
sudo make
sudo make install
更换ubuntu Python版本
添加
sudo update-alternatives –install /usr/bin/python python /usr/bin/python3.8 3
显示列表
sudo update-alternatives –config python
移除
sudo update-alternatives –remove python /usr/bin/python3