def region(self, country: str, state: str = None) -> "Stations":
        """
        Filter weather stations by country/region code
        """

        # Create temporal instance
        temp = copy(self)

        # Country code
        temp._data = temp._data[temp._data["country"] == country]

        # State code
        if state is not None:
            temp._data = temp._data[temp._data["region"] == state]

        # Return self
        return temp

        Filter weather stations by country/region code
        
meteostat/interface/stations.py