add station_type check for local stored data

src/data_preparation.py

@@ -80,12 +80,20 @@ class DataPrep(object):
             data = self._slice_prep(xr.open_dataarray(file_name))
             self.data = self.check_for_negative_concentrations(data)
             self.meta = pd.read_csv(meta_file, index_col=0)
+            if self.station_type is not None:
+                self.check_station_type()
         except FileNotFoundError as e:
             logging.warning(e)
             data, self.meta = self.download_data_from_join(file_name, meta_file)
             data = self._slice_prep(data)
             self.data = self.check_for_negative_concentrations(data)
 
+    def check_station_type(self):
+        if self.meta.at["station_type", self.station[0]] != self.station_type:
+            self.data = None
+            self.meta = None
+            raise join.EmptyQueryResult
+
     def download_data_from_join(self, file_name: str, meta_file: str) -> [xr.DataArray, pd.DataFrame]:
         """
         Download data from TOAR database using the JOIN interface.
@@ -114,7 +122,7 @@ class DataPrep(object):
 
     def __repr__(self):
         return f"Dataprep(path='{self.path}', network='{self.network}', station={self.station}, " \
-               f"variables={self.variables}, **{self.kwargs})"
+               f"variables={self.variables}, station_type='{self.station_type}', **{self.kwargs})"
 
     def interpolate(self, dim: str, method: str = 'linear', limit: int = None,
                     use_coordinate: Union[bool, str] = True, **kwargs):