http://www.cnblogs.com/huxi/archive/2010/07/04/1771073.html
http://www.pythonclub.org/python-basic/regexp
http://blog.csdn.net/jgood/article/details/4277902
http://developer.51cto.com/art/201002/184746.htm
http://www.360doc.com/content/11/0831/17/2660674_144802284.shtml
