Requirements:

	lxml - python libxml binding

	it needs to installing the following packages before install lxml.

    *  libxml 2.6.21 or later. It can be found here: http://xmlsoft.org/downloads.html
    *  libxslt 1.1.15 or later. It can be found here: http://xmlsoft.org/XSLT/downloads.html
		
	If you use Ubuntu, here is what you need to do.
	
	$ apt-get install libxml2-dev libxslt1-dev
	$ eazy_install lxml

Example:

	product = c('http://www.google.com.tw').find("/foo/bar/").working_prodcut
	print product.content