From 0d2bed24df61b4be29a3d1becbf024f808c1b402 Mon Sep 17 00:00:00 2001
From: ShaharNaveh <>
Date: Mon, 26 Apr 2021 23:21:23 +0300
Subject: [PATCH 1/2] TST: Regression test for #33765

---
 pandas/tests/frame/test_arithmetic.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/pandas/tests/frame/test_arithmetic.py b/pandas/tests/frame/test_arithmetic.py
index c6816fa6481f4..1dbd842bee6b6 100644
--- a/pandas/tests/frame/test_arithmetic.py
+++ b/pandas/tests/frame/test_arithmetic.py
@@ -12,6 +12,7 @@
 import pandas as pd
 from pandas import (
     DataFrame,
+    Index,
     MultiIndex,
     Series,
 )
@@ -1782,3 +1783,22 @@ def test_inplace_arithmetic_series_update():
 
     expected = DataFrame({"A": [2, 3, 4]})
     tm.assert_frame_equal(df, expected)
+
+
+def test_arithemetic_multiindex_align():  # Needs a better name
+    """
+    Regression test for: https://github.com/pandas-dev/pandas/issues/33765
+    """
+    df1 = DataFrame(
+        [[1]],
+        index=["a"],
+        columns=MultiIndex.from_product([[0], [1]], names=["a", "b"]),
+    )
+    df2 = DataFrame([[1]], index=["a"], columns=Index([0], name="a"))
+    expected = DataFrame(
+        [[0]],
+        index=["a"],
+        columns=MultiIndex.from_product([[0], [1]], names=["a", "b"]),
+    )
+    result = df1 - df2
+    tm.assert_frame_equal(result, expected)

From 4da5fc60646bd20776caa6f13176c10cf5822c95 Mon Sep 17 00:00:00 2001
From: ShaharNaveh <>
Date: Thu, 29 Apr 2021 16:06:40 +0300
Subject: [PATCH 2/2] Removed comment

---
 pandas/tests/frame/test_arithmetic.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/frame/test_arithmetic.py b/pandas/tests/frame/test_arithmetic.py
index e207af142df87..9c95b2f944d18 100644
--- a/pandas/tests/frame/test_arithmetic.py
+++ b/pandas/tests/frame/test_arithmetic.py
@@ -1795,7 +1795,7 @@ def test_inplace_arithmetic_series_update():
     tm.assert_frame_equal(df, expected)
 
 
-def test_arithemetic_multiindex_align():  # Needs a better name
+def test_arithemetic_multiindex_align():
     """
     Regression test for: https://github.com/pandas-dev/pandas/issues/33765
     """