python webkit非同期ページデータのキャプチャ

#!/usr/bin/python
from ghost import Ghost


class FetcherCartoon:

	def getCartoonUrl(self, url):
		
		if url is None:
			return false
		#todo many decide about url
		
		ghost = Ghost()
		#open webkit
		ghost.open(url)
		#exceute javascript and get what you want 
		result, resources = ghost.evaluate("document.getElementById('cp_image').getAttribute('src');")
		del resources
		return result

if __name__ == "__main__":
	url = 'http://www.dm5.com/m136836-p3/'
	result = None
	fetcher = FetcherCartoon()


	result = fetcher.getCartoonUrl(url)
	print result