simpler solution

Author: Petroncini

pandas/core/groupby/ops.py

@@ -371,24 +371,9 @@ def _call_cython_op(
 
         is_datetimelike = dtype.kind in "mM"
 
-        if self.how in ["any", "all"]:
-            if mask is None:
-                mask = isna(values)
-            values = values.astype(bool, copy=False).view(np.int8)
-            is_numeric = True
-
         if is_datetimelike:
-            # Handle NaT values correctly
-            if self.how == "any" and mask is not None:
-                # For "any", we want True only if there's at least one non-NaT value
-                values = (~mask).astype(np.int8)  # Convert mask to int8
-            elif self.how == "all" and mask is not None:
-                # For "all", we want True only if all values are non-NaT
-                values = (~mask).all(axis=1, keepdims=True).astype(np.int8)
-                is_numeric = True
-            else:
-                values = values.view("int64")  # Handle other cases appropriately
-
+            values = values.view("int64")
+            is_numeric = True
         elif dtype.kind == "b":
             values = values.view("uint8")
         if values.dtype == "float16":
@@ -400,6 +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)