在安装numpy库时，出现了这样的错误：

安装命令：

easy_install numpy

错误：

MacdeMacBook-Pro-3:python mac$ easy_install numpy
error: can't create or remove files in install directory

The following error occurred while trying to add or remove files in the
installation directory:

    [Errno 13] Permission denied: '/Library/Python/2.7/site-packages/test-easy-install-785.write-test'

什么原因呢？通过分析错误提示，"[Errno 13] Permission denied:"原来是权限问题，需要超级管理员权限：

sudo easy_install numpy

安装成功：

MacdeMacBook-Pro-3:python mac$ sudo easy_install numpy
Password:
Searching for numpy
Best match: numpy 1.6.2
Adding numpy 1.6.2 to easy-install.pth file

Using /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python
Processing dependencies for numpy
Finished processing dependencies for numpy
MacdeMacBook-Pro-3:python mac$