def _create_base_string(method, base, params):
 normalized_qs = _normalize_params(params)
 return _join_by_ampersand(method, base, normalized_qs)

def _create_base_string ( method , base , params ) : normalized_qs = _normalize_params ( params ) return _join_by_ampersand ( method , base , normalized_qs )
returns base string for hmac-sha1 signature as specified in: URL#rfc .