Easily download, build, install, upgrade, and uninstall Python packages
它是一个对python的包进行安装，升级，卸载的模块（包）
python2.x:
wget https://bootstrap.pypa.io/ez_setup.py -O - | sudo python
python3.x
wget https://bootstrap.pypa.io/ez_setup.py -O - | sudo python3.4
若是你在没有安装该模块的前提下，安装别的包，会出错提示：
ImportError: No module named setuptools
原文：http://my.oschina.net/deanzhao/blog/317603