Ubuntu默认安装了Python2.7和3.5
输入命令python
按Ctrl+D退出python命令行
输入命令sudo add-apt-repository ppa:jonathonf/python-3.6
按Enter确认
输入命令sudo apt-get update
输入命令sudo apt-get install python3.6
按Y确认
调整Python3的优先级，使得3.6优先级较高
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.5 1
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 2
更改默认值，python默认为Python2，现在修改为Python3
sudo update-alternatives --install /usr/bin/python python /usr/bin/python2 100
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 150
此时再输入命令python
可以看到已经是Python3.6了！
输入命令sudo apt-get install python3-pip安装pip
输入命令sudo pip3 install --upgrade pip更新pip
在3.6后，pip3的使用方法
On Unix-like systems use:
python3.6 -m pip install [Package_to_install]
添加Selenum模块
sudo -H pip install selenium
添加Appium模块
sudo -H pip install Appium-Python-Client