def link_href(self, rel):
        """Look for link with specified rel, return href from it or None."""
        link = self.link(rel)
        if (link is not None):
            link = link['href']
        return(link)
def link_href ( self , rel ) : link = self . link ( rel ) if ( link is not None ) : link = link [ 'href' ] return ( link )
Look for link with specified rel, return href from it or None.