def _nsattr(self, attr, ns=None):
        ''' returns an attribute name w/ namespace prefix'''
        if ns is None:
            return attr
        return '{' + self._ns[ns] + '}' + attr
def _nsattr(self, attr, ns=None):
        ''' returns an attribute name w/ namespace prefix'''
        if ns is None:
            return attr
        return '{' + self._ns[ns] + '}' + attr
def _nsattr ( self , attr , ns = None ) : if ns is None : return attr return '{' + self . _ns [ ns ] + '}' + attr
returns an attribute name w/ namespace prefix
returns an attribute name w / namespace prefix