软件源：
先换掉更新源，加速安装。
PS：之前因为没有注意到版本的问题 一直用的wheezy和jessis 后来才发现自己树莓派版本是stretch
一定要注意这个坑
查看自己树莓派的版本：lsb_release -c
Codename: stretch
sudo nano /etc/apt/sources.list
```
deb http://mirrors.aliyun.com/raspbian/raspbian/ stretch main non-free contrib
deb-src http://mirrors.aliyun.com/raspbian/raspbian/ stretch main non-free contrib
deb http://mirrors.neusoft.edu.cn/raspbian/raspbian/ stretch main contrib non-free rpi
deb-src http://mirrors.neusoft.edu.cn/raspbian/raspbian/ stretch main contrib non-free rpi
deb http://mirrors.ustc.edu.cn/raspbian/raspbian/ stretch main contrib non-free rpi
deb-src http://mirrors.ustc.edu.cn/raspbian/raspbian/ stretch main contrib non-free rpi
```
wheezy
deb http://mirrors.aliyun.com/raspbian/raspbian/ wheezy main non-free contrib
deb-src http://mirrors.aliyun.com/raspbian/raspbian/ wheezy main non-free contrib
deb http://mirrors.neusoft.edu.cn/raspbian/raspbian/ wheezy main contrib non-free rpi
deb-src http://mirrors.neusoft.edu.cn/raspbian/raspbian/ wheezy main contrib non-free rpi
deb http://mirrors.ustc.edu.cn/raspbian/raspbian/ wheezy main contrib non-free rpi
deb-src http://mirrors.ustc.edu.cn/raspbian/raspbian/ wheezy main contrib non-free rpi
更多更新源在此；
http://www.raspbian.org/RaspbianMirrors