BeautifulSoup.py 文件源码

def search(self, markup):
        #print 'looking for %s in %s' % (self, markup)
        found = None
        # If given a list of items, scan it for a text element that
        # matches.
        if isList(markup) and not isinstance(markup, Tag):
            for element in markup:
                if isinstance(element, NavigableString) \
                       and self.search(element):
                    found = element
                    break
        # If it's a Tag, make sure its name or attributes match.
        # Don't bother with Tags if we're searching for text.
        elif isinstance(markup, Tag):
            if not self.text:
                found = self.searchTag(markup)
        # If it's text, make sure the text matches.
        elif isinstance(markup, NavigableString) or \
                 isString(markup):
            if self._matches(markup, self.text):
                found = markup
        else:
            raise Exception, "I don't know how to match against a %s" \
                  % markup.__class__
        return found