换源
（1）编辑sources.list文件
sudo gedit /etc/apt/sources.list
（2）更换清华源
打开文件后，直接删除之前的文件，把下面的粘上去
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-updates main restricted universe multiverse deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-updates main restricted universe multiverse deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-security main restricted universe multiverse deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-security main restricted universe multiverse deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-backports main restricted universe multiverse deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic-backports main restricted universe multiverse deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic main universe restricted deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ bionic main universe restricted
3）更新源
sudo apt-get update
添加中文输入法
安装ibus-pinyin
sudo apt-get install ibus-pinyin
安装完成后
ibus-setup
切换到输入法选项卡，点击添加按钮，选择汉语，有两个选项，选择Pinyin
python2,3切换
终端输入python，打开的是python2，不是python3
which python3
查看安装python的目录：/usr/local/bin/python3
打开/usr/bin
cd /usr/bin
移除之前的链接
rm python
建立与python3的软连接
sudo ln -s /usr/local/bin/python3 /usr/bin/python
最后
reboot
重启
