BUG: pivot_table not returning correct type when margin=True and aggfunc='mean'

doc/source/whatsnew/v1.0.0.rst

@@ -186,6 +186,7 @@ Reshaping
 
 -
 -
+- Bug in :meth:`pivot_table` not returning correct type ``float`` when ``margins=True`` and ``aggfunc='mean'`` (:issue:`24893`)
 
 Sparse
 ^^^^^^

pandas/core/reshape/pivot.py

@@ -252,9 +252,12 @@ def _add_margins(
 
     row_names = result.index.names
     try:
+        # check the result column and leave floats
         for dtype in set(result.dtypes):
             cols = result.select_dtypes([dtype]).columns
-            margin_dummy[cols] = margin_dummy[cols].astype(dtype)
+            margin_dummy[cols] = margin_dummy[cols].apply(
+                maybe_downcast_to_dtype, args=(dtype,)
+            )
         result = result.append(margin_dummy)
     except TypeError:
 

pandas/tests/reshape/test_pivot.py

@@ -1630,6 +1630,25 @@ def test_categorical_margins_category(self, observed):
         table = df.pivot_table("x", "y", "z", dropna=observed, margins=True)
         tm.assert_frame_equal(table, expected)
 
+    def test_margins_casted_to_float(self, observed):
+        # GH #24893
+        df = pd.DataFrame(
+            {
+                "A": [2, 4, 6, 8],
+                "B": [1, 4, 5, 8],
+                "C": [1, 3, 4, 6],
+                "D": ["X", "X", "Y", "Y"],
+            }
+        )
+
+        result = pd.pivot_table(df, index="D", margins=True)
+        expected = pd.DataFrame(
+            {"A": [3, 7, 5], "B": [2.5, 6.5, 4.5], "C": [2, 5, 3.5]},
+            index=pd.Index(["X", "Y", "All"], name="D"),
+        )
+        table = result
+        tm.assert_frame_equal(result, expected)
+
     def test_categorical_aggfunc(self, observed):
         # GH 9534
         df = pd.DataFrame(