Linux安装python3:
sudo apt-get install python3.5
安装python库
sudo apt-get install python3-setuptools
sudo easy_install3 pip
sudo pip3 install pyserial（pyserial替换成需要的第三方库）
1、卸载python3.4
sudo apt-get remove python3.4
2、卸载python3.4及其依赖
sudo apt-get remove --auto-remove python3.4
3、清除python3.4
sudo apt-get purge python3.4
or
sudo apt-get purge --auto-remove python3.4