Resolve "Execution order of interpolate and transform"

See merge request toar/machinelearningtools!51

src/data_handling/data_generator.py

@@ -182,9 +182,9 @@ class DataGenerator(keras.utils.Sequence):
             logging.info(f"load not pickle data for {station}")
             data = DataPrep(self.data_path, self.network, station, self.variables, station_type=self.station_type,
                             **self.kwargs)
-            data.interpolate(self.interpolate_dim, method=self.interpolate_method, limit=self.limit_nan_fill)
             if self.transformation is not None:
                 data.transform("datetime", **helpers.dict_pop(self.transformation, "scope"))
+            data.interpolate(self.interpolate_dim, method=self.interpolate_method, limit=self.limit_nan_fill)
             data.make_history_window(self.interpolate_dim, self.window_history_size)
             data.make_labels(self.target_dim, self.target_var, self.interpolate_dim, self.window_lead_time)
             data.history_label_nan_remove(self.interpolate_dim)