Ordering columns in the Druid pandas df

TODO.md

@@ -4,7 +4,6 @@ List of TODO items for Panoramix
 ## Features
 * **URL shortner**
 * **Dashboard URL filters:** `{dash_url}#fltin__fieldname__value1,value2`
-* **Browser history in explore.html:** use location.hash to manage query history
 * **Default slice:** choose a default slice for the dataset instead of default endpoint
 * **refresh freq**: specifying the refresh frequency of a dashboard and specific slices within it, some randomization would be nice
 * **Color hash in JS:** it'd be nice to use the same hash function for color attribution of series

panoramix/models.py

@@ -916,6 +916,15 @@ class Datasource(Model, AuditMixinNullable, Queryable):
         client.groupby(**qry)
         query_str += json.dumps(client.query_dict, indent=2)
         df = client.export_pandas()
+
+        # Reordering columns
+        cols = []
+        if 'timestamp' in df.columns:
+            cols += ['timestamp']
+        cols += [col for col in groupby if col in df.columns]
+        cols += [col for col in metrics if col in df.columns]
+        cols += [col for col in df.columns if col in cols]
+        df = df[cols]
         return QueryResult(
             df=df,
             query=query_str,