<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def coords(self) -> Iterator[Tuple[float, float, float]]: """Iterates on longitudes, latitudes and altitudes. """

        data = self.data[self.data.longitude.notnull()]
        yield from zip(data["longitude"], data["latitude"], data["altitude"])