gistfile1.txt

    def extract_tag_words(self, elem):
        """Extract tag words form the given element."""
        attr_extractors = {
            "alt": lambda elem: elem["alt"],
            "name": lambda elem: elem["name"],
            "title": lambda elem: elem["title"],
            "placeholder": lambda elem: elem["placeholder"],
            "src": lambda elem: elem["src"].split('/')[-1],
            "href": lambda elem: elem["href"].split('/')[-1],
            "text": str,
            "value": lambda elem: elem["value"]
        }

        extractable_attrs = collections.defaultdict(list, {
            "img": ["alt", "title", "src"],
            "a": ["title", "href", "text"],
            "input": ["name", "placeholder"],
            "textarea": ["name", "placeholder"],
            "button": ["text", "value"]
        })

        return (attr_extractors[attr](elem)
                for attr in extractable_attrs[elem.tag_name()]
                if attr in elem or attr == "text")