如果提示缺少串口模块，需要用以下命令安装pyserial
user@Phytium-Pi:/opt/test/uart$ pip install pyserial


user@Phytium-Pi:/opt/test/uart$ pip install pyserial
Collecting pyserial
  Downloading pyserial-3.5-py2.py3-none-any.whl (90 kB)
     |████████████████████████████████| 90 kB 237 kB/s 
Installing collected packages: pyserial
  WARNING: The scripts pyserial-miniterm and pyserial-ports are installed in '/home/user/.local/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed pyserial-3.5
user@Phytium-Pi:/opt/test/uart$