From 1907b35b405d3acfea55f308d6ccfbbb6dd9d6f5 Mon Sep 17 00:00:00 2001
From: 40gilad <40gilad.shenkar@gmail.com>
Date: Sun, 8 Sep 2024 13:04:36 +0300
Subject: [PATCH 1/3] fix issue #59712

---
 pandas/core/groupby/ops.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/pandas/core/groupby/ops.py b/pandas/core/groupby/ops.py
index da80969b613cd..8aa715682be19 100644
--- a/pandas/core/groupby/ops.py
+++ b/pandas/core/groupby/ops.py
@@ -371,14 +371,6 @@ def _call_cython_op(
 
         is_datetimelike = dtype.kind in "mM"
 
-        if is_datetimelike:
-            values = values.view("int64")
-            is_numeric = True
-        elif dtype.kind == "b":
-            values = values.view("uint8")
-        if values.dtype == "float16":
-            values = values.astype(np.float32)
-
         if self.how in ["any", "all"]:
             if mask is None:
                 mask = isna(values)
@@ -392,6 +384,14 @@ def _call_cython_op(
             values = values.astype(bool, copy=False).view(np.int8)
             is_numeric = True
 
+        if is_datetimelike:
+            values = values.view("int64")
+            is_numeric = True
+        elif dtype.kind == "b":
+            values = values.view("uint8")
+        if values.dtype == "float16":
+            values = values.astype(np.float32)
+
         values = values.T
         if mask is not None:
             mask = mask.T

From c5c67ddcc44cd67391a0ddb09f97ca8a0d76c910 Mon Sep 17 00:00:00 2001
From: 40gilad <40gilad.shenkar@gmail.com>
Date: Sun, 8 Sep 2024 13:38:39 +0300
Subject: [PATCH 2/3] fix issue #59712

---
 pandas/core/groupby/ops.py | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/pandas/core/groupby/ops.py b/pandas/core/groupby/ops.py
index 8aa715682be19..703c270132a02 100644
--- a/pandas/core/groupby/ops.py
+++ b/pandas/core/groupby/ops.py
@@ -371,19 +371,6 @@ def _call_cython_op(
 
         is_datetimelike = dtype.kind in "mM"
 
-        if self.how in ["any", "all"]:
-            if mask is None:
-                mask = isna(values)
-            if dtype == object:
-                if kwargs["skipna"]:
-                    # GH#37501: don't raise on pd.NA when skipna=True
-                    if mask.any():
-                        # mask on original values computed separately
-                        values = values.copy()
-                        values[mask] = True
-            values = values.astype(bool, copy=False).view(np.int8)
-            is_numeric = True
-
         if is_datetimelike:
             values = values.view("int64")
             is_numeric = True
@@ -398,6 +385,19 @@ def _call_cython_op(
             if result_mask is not None:
                 result_mask = result_mask.T
 
+        if self.how in ["any", "all"]:
+            if mask is None:
+                mask = isna(values)
+            if dtype == object:
+                if kwargs["skipna"]:
+                    # GH#37501: don't raise on pd.NA when skipna=True
+                    if mask.any():
+                        # mask on original values computed separately
+                        values = values.copy()
+                        values[mask] = True
+            values = values.astype(bool, copy=False).view(np.int8)
+            is_numeric = True
+
         out_shape = self._get_output_shape(ngroups, values)
         func = self._get_cython_function(self.kind, self.how, values.dtype, is_numeric)
         values = self._get_cython_vals(values)

From d69350d9143930ab23d2e32f48a195d286f64a97 Mon Sep 17 00:00:00 2001
From: 40gilad <40gilad.shenkar@gmail.com>
Date: Sun, 8 Sep 2024 14:46:47 +0300
Subject: [PATCH 3/3] added test func
 test_groupby_any_timedelta_with_all_nulls()

---
 pandas/tests/groupby/test_grouping.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/pandas/tests/groupby/test_grouping.py b/pandas/tests/groupby/test_grouping.py
index fc2a8a970010a..b1d84f8ac4657 100644
--- a/pandas/tests/groupby/test_grouping.py
+++ b/pandas/tests/groupby/test_grouping.py
@@ -1180,3 +1180,15 @@ def test_grouping_by_key_is_in_axis():
     result = gb.sum()
     expected = DataFrame({"a": [1, 2], "b": [1, 2], "c": [7, 5]})
     tm.assert_frame_equal(result, expected)
+
+def test_groupby_any_timedelta_with_all_nulls():
+    # Create a DataFrame with timedelta values, including NaT (null timedelta)
+    df = pd.DataFrame({
+        'timedelta': [pd.Timedelta(days=1), pd.NaT],
+        'group': [0, 1]
+    })
+    result = df.groupby('group')['timedelta'].any()
+
+    # Expected behavior: group 1 should return False because it has all null values
+    expected = pd.Series([True, False], index=[0, 1])
+    pd.testing.assert_series_equal(result, expected)