def to_json(self, na='null', show_bbox=False, **kwargs):
        return json.dumps(self._to_geo(na=na, show_bbox=show_bbox), **kwargs)
Returns a GeoJSON string representation of the GeoDataFrame.
dataset/ETHPy150Open geopandas/geopandas/geopandas/geodataframe.py/GeoDataFrame.to_json