安装python3.5

安装python3.5：

添加 PPA：

sudo add-apt-repository ppa:fkrull/deadsnakes

sudo apt-get update

sudo apt-get install python3.5

sudo apt-get install python3.5-dev

sudo cp /usr/bin/python /usr/bin/python_bak，先备份

sudo rm /usr/bin/python,删除

sudo ln -s /usr/bin/python3.5 /usr/bin/python，默认设置成python3.5

安装新版pip：

wget https://bootstrap.pypa.io/get-pip.py

sudo python3 get-pip.py

sudo pip3 install setuptools --upgrade

sudo pip3 install ipython[all]