python安装serial串口模块，No module named 'serial.tools'错误

1.安装serial模块：

 pip install serial

   如果报错：ERROR: Cannot uninstall 'PyYAML'. It is a distutils installed project and thus we cannot accurately

不能覆盖已经存在的模块就使用下面的忽视已安装模块安装：

 pip install --ignore-installed serial

2.安装pyserial模块，不然会报No module named 'serial.tools'错误：

pip install pyserial