def _rfc3339_to_datetime(dt_str):
 return datetime.datetime.strptime(dt_str, _RFC3339_MICROS).replace(tzinfo=UTC)

def _rfc3339_to_datetime ( dt_str ) : return datetime . datetime . strptime ( dt_str , _RFC3339_MICROS ) . replace ( tzinfo = UTC )
convert a microsecond-precision timetamp to a native datetime .