remove a tag or tags from a symbol 
        
        Parameters
        ----------
        tags : str or [str,]
            Tags to be removed

def del_tags(self, tags):
        """ remove a tag or tags from a symbol 
        
        Parameters
        ----------
        tags : str or [str,]
            Tags to be removed
        """
        # SQLA Adding a SymbolTag object, feels awkward/uneccessary.
        # Should I be implementing this functionality a different way?

        if isinstance(tags, (str, unicode)):
            tags = [tags]

        objs = object_session(self)

        docommit = False
        for symboltag in self.tags:
            if symboltag.tag in tags:
                objs.delete(symboltag)
                docommit = True

        
        if docommit:
            objs.commit()