fix: pivot table timestamp grouping (apache#10774)

* fix: pivot table timestamp grouping

* address comments

superset/viz.py

@@ -27,7 +27,7 @@
 import math
 import re
 from collections import defaultdict, OrderedDict
-from datetime import datetime, timedelta
+from datetime import date, datetime, timedelta
 from itertools import product
 from typing import (
     Any,
@@ -602,11 +602,11 @@ class TableViz(BaseViz):
 
     def process_metrics(self) -> None:
         """Process form data and store parsed column configs.
-           1. Determine query mode based on form_data params.
-                - Use `query_mode` if it has a valid value
-                - Set as RAW mode if `all_columns` is set
-                - Otherwise defaults to AGG mode
-           2. Determine output columns based on query mode.
+        1. Determine query mode based on form_data params.
+             - Use `query_mode` if it has a valid value
+             - Set as RAW mode if `all_columns` is set
+             - Otherwise defaults to AGG mode
+        2. Determine output columns based on query mode.
         """
         # Verify form data first: if not specifying query mode, then cannot have both
         # GROUP BY and RAW COLUMNS.
@@ -813,6 +813,31 @@ def get_aggfunc(
         # only min and max work properly for non-numerics
         return aggfunc if aggfunc in ("min", "max") else "max"
 
+    @staticmethod
+    def _format_datetime(value: Union[pd.Timestamp, datetime, date, str]) -> str:
+        """
+        Format a timestamp in such a way that the viz will be able to apply
+        the correct formatting in the frontend.
+
+        :param value: the value of a temporal column
+        :return: formatted timestamp if it is a valid timestamp, otherwise
+                 the original value
+        """
+        tstamp: Optional[pd.Timestamp] = None
+        if isinstance(value, pd.Timestamp):
+            tstamp = value
+        if isinstance(value, datetime) or isinstance(value, date):
+            tstamp = pd.Timestamp(value)
+        if isinstance(value, str):
+            try:
+                tstamp = pd.Timestamp(value)
+            except ValueError:
+                pass
+        if tstamp:
+            return f"__timestamp:{datetime_to_epoch(tstamp)}"
+        # fallback in case something incompatible is returned
+        return cast(str, value)
+
     def get_data(self, df: pd.DataFrame) -> VizData:
         if df.empty:
             return None
@@ -828,15 +853,10 @@ def get_data(self, df: pd.DataFrame) -> VizData:
         groupby = self.form_data.get("groupby") or []
         columns = self.form_data.get("columns") or []
 
-        def _format_datetime(value: Any) -> Optional[str]:
-            if isinstance(value, str):
-                return f"__timestamp:{datetime_to_epoch(pd.Timestamp(value))}"
-            return None
-
         for column_name in groupby + columns:
             column = self.datasource.get_column(column_name)
-            if column and column.type in ("DATE", "DATETIME", "TIMESTAMP"):
-                ts = df[column_name].apply(_format_datetime)
+            if column and column.is_temporal:
+                ts = df[column_name].apply(self._format_datetime)
                 df[column_name] = ts
 
         if self.form_data.get("transpose_pivot"):

tests/viz_tests.py

@@ -16,7 +16,7 @@
 # under the License.
 # isort:skip_file
 import uuid
-from datetime import datetime
+from datetime import date, datetime, timezone
 import logging
 from math import nan
 from unittest.mock import Mock, patch
@@ -1345,6 +1345,38 @@ def test_get_aggfunc_non_numeric(self):
             == "min"
         )
 
+    def test_format_datetime_from_pd_timestamp(self):
+        tstamp = pd.Timestamp(datetime(2020, 9, 3, tzinfo=timezone.utc))
+        assert (
+            viz.PivotTableViz._format_datetime(tstamp) == "__timestamp:1599091200000.0"
+        )
+
+    def test_format_datetime_from_datetime(self):
+        tstamp = datetime(2020, 9, 3, tzinfo=timezone.utc)
+        assert (
+            viz.PivotTableViz._format_datetime(tstamp) == "__timestamp:1599091200000.0"
+        )
+
+    def test_format_datetime_from_date(self):
+        tstamp = date(2020, 9, 3)
+        assert (
+            viz.PivotTableViz._format_datetime(tstamp) == "__timestamp:1599091200000.0"
+        )
+
+    def test_format_datetime_from_string(self):
+        tstamp = "2020-09-03T00:00:00"
+        assert (
+            viz.PivotTableViz._format_datetime(tstamp) == "__timestamp:1599091200000.0"
+        )
+
+    def test_format_datetime_from_invalid_string(self):
+        tstamp = "abracadabra"
+        assert viz.PivotTableViz._format_datetime(tstamp) == tstamp
+
+    def test_format_datetime_from_int(self):
+        assert viz.PivotTableViz._format_datetime(123) == 123
+        assert viz.PivotTableViz._format_datetime(123.0) == 123.0
+
 
 class TestDistributionPieViz(SupersetTestCase):
     base_df = pd.DataFrame(