Fix patching table with pd.Timestamp values (#5650)

* fix patching with a dataframe without monotonic index

* fix patching pd.Timestamp values

panel/tests/widgets/test_tables.py

@@ -1271,6 +1271,29 @@ def test_tabulator_patch_ranges(document, comm):
         if col != 'index':
             np.testing.assert_array_equal(table.value[col].values, expected[col])
 
+def test_tabulator_patch_with_timestamp(document, comm):
+    # https://github.com/holoviz/panel/issues/5555
+    df = pd.DataFrame(dict(A=pd.to_datetime(['1980-01-01', '1980-01-02'])))
+    table = Tabulator(df)
+
+    model = table.get_root(document, comm)
+
+    table.patch({'A': [(0, pd.Timestamp('2021-01-01'))]})
+
+    expected = {
+        'index': np.array([0, 1]),
+        'A': np.array(['2021-01-01T00:00:00.000000000',
+                       '1980-01-02T00:00:00.000000000'],
+                      dtype='datetime64[ns]')
+    }
+    for col, values in model.source.data.items():
+        if col == 'A':
+            expected_array = expected[col].astype(np.int64) / 10e5
+        else:
+            expected_array = expected[col]
+        np.testing.assert_array_equal(values, expected_array)
+        if col != 'index':
+            np.testing.assert_array_equal(table.value[col].values, expected[col])
 
 def test_tabulator_stream_series_paginated_not_follow(document, comm):
     df = makeMixedDataFrame()

panel/widgets/tables.py

@@ -29,7 +29,7 @@
 from ..io.state import state
 from ..reactive import Reactive, ReactiveData
 from ..util import (
-    clone_model, isdatetime, lazy_load, updating,
+    clone_model, datetime_as_utctimestamp, isdatetime, lazy_load, updating,
 )
 from .base import Widget
 from .button import Button
@@ -822,6 +822,8 @@ def patch(self, patch_value, as_index=True):
                         self.value.loc[data_ind, k] = value
                     else:
                         self.value.iloc[data_ind, columns.index(k)] = value
+                    if isinstance(value, pd.Timestamp):
+                        value = datetime_as_utctimestamp(value)
                     values.append((patch_ind, value))
                 patches[k] = values
             self._patch(patches)