Fix bug when graph_timestamp_map doesn't exist

Author: staadecker

switch_model/tools/graph/main.py

@@ -205,7 +205,7 @@ def timestamp(self, df, timestamp_col="timestamp"):
         - hour: The hour of the timestamp (US/Pacific timezone)
         """
         timepoints = self.tools.get_dataframe(
-            "timepoints.csv", from_inputs=True, drop_scenario_info=False
+            filename="timepoints.csv", from_inputs=True, drop_scenario_info=False
         )
         timeseries = self.tools.get_dataframe(
             filename="timeseries.csv", from_inputs=True, drop_scenario_info=False
@@ -241,8 +241,8 @@ def timestamp(self, df, timestamp_col="timestamp"):
                 on="timestamp",
             )
         except FileNotFoundError:
-            timestamp_mapping["time_row"] = timestamp_mapping["period"]
-            timestamp_mapping["time_column"] = timestamp_mapping["timeseries"]
+            df["time_row"] = df["period"]
+            df["time_column"] = df["timeseries"]
 
         # Add datetime and hour column
         df["datetime"] = (