树莓派上面import numpy失败的解决办法

错误信息：

ImportError: 
Importing the multiarray numpy extension module failed.  Most
likely you are trying to import a failed build of numpy.
If you're working with a numpy git repo, try `git clean -xdf` (removes all
files not under version control).  Otherwise reinstall numpy.

Original error was: libf77blas.so.3: cannot open shared object file: No such file or directory

搜了一下这个libf77blas.so.3, 搜出一个libatlas-base-dev 软件包文件清单里面有这个, 于是就apt-get install libatlas-base-dev, 安装完成后再尝试import numpy，可以了。