Handling empty dataframe

main.py

@@ -84,7 +84,14 @@ def get_data(query):
             [KariosConstants.VALUES_KEY]
         df = DataFrame.from_dict(data)
         logger.debug("Dataframe --> {}".format(df.head()))
-        df.columns = [KariosConstants.TIMESTAMP_COLUMN_NAME, list(config[KariosConstants.TAG_HIERARCHY_KEY].keys())[0]]
+
+        if len(df) > 0:
+            df.columns = [KariosConstants.TIMESTAMP_COLUMN_NAME, list(config[KariosConstants.TAG_HIERARCHY_KEY].keys())
+            [0]]
+        else:
+            logger.warn("The dataframe is empty!")
+            df = DataFrame(columns=[KariosConstants.TIMESTAMP_COLUMN_NAME, list(config[KariosConstants.
+                                                                                TAG_HIERARCHY_KEY].keys())[0]])
         return df
     else:
         raise Exception(response.json()[KariosConstants.ERRORS_KEY])