From 22831be75ada88b9b57ad1b9d529feeeb671cd86 Mon Sep 17 00:00:00 2001
From: Marco Gorelli <33491632+MarcoGorelli@users.noreply.github.com>
Date: Wed, 19 Feb 2025 10:53:53 +0000
Subject: [PATCH] remove unused dtype from MultiIndex constructor

---
 doc/source/whatsnew/v3.0.0.rst               | 1 +
 pandas/core/indexes/multi.py                 | 1 -
 pandas/tests/indexing/multiindex/test_loc.py | 4 ++--
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/source/whatsnew/v3.0.0.rst b/doc/source/whatsnew/v3.0.0.rst
index 4d9a45abe17cd..9d732b0fce450 100644
--- a/doc/source/whatsnew/v3.0.0.rst
+++ b/doc/source/whatsnew/v3.0.0.rst
@@ -357,6 +357,7 @@ Other API changes
 - Made ``dtype`` a required argument in :meth:`ExtensionArray._from_sequence_of_strings` (:issue:`56519`)
 - Passing a :class:`Series` input to :func:`json_normalize` will now retain the :class:`Series` :class:`Index`, previously output had a new :class:`RangeIndex` (:issue:`51452`)
 - Removed :meth:`Index.sort` which always raised a ``TypeError``. This attribute is not defined and will raise an ``AttributeError`` (:issue:`59283`)
+- Unused ``dtype`` argument has been removed from the :class:`MultiIndex` constructor (:issue:`60962`)
 - Updated :meth:`DataFrame.to_excel` so that the output spreadsheet has no styling. Custom styling can still be done using :meth:`Styler.to_excel` (:issue:`54154`)
 - pickle and HDF (``.h5``) files created with Python 2 are no longer explicitly supported (:issue:`57387`)
 - pickled objects from pandas version less than ``1.0.0`` are no longer supported (:issue:`57155`)
diff --git a/pandas/core/indexes/multi.py b/pandas/core/indexes/multi.py
index dc48cd1ed958e..d6b1028d9e78e 100644
--- a/pandas/core/indexes/multi.py
+++ b/pandas/core/indexes/multi.py
@@ -305,7 +305,6 @@ def __new__(
         codes=None,
         sortorder=None,
         names=None,
-        dtype=None,
         copy: bool = False,
         name=None,
         verify_integrity: bool = True,
diff --git a/pandas/tests/indexing/multiindex/test_loc.py b/pandas/tests/indexing/multiindex/test_loc.py
index ec9767aa4bab4..1d3258ab18a61 100644
--- a/pandas/tests/indexing/multiindex/test_loc.py
+++ b/pandas/tests/indexing/multiindex/test_loc.py
@@ -105,7 +105,7 @@ def test_loc_getitem_series(self):
         empty = Series(data=[], dtype=np.float64)
         expected = Series(
             [],
-            index=MultiIndex(levels=index.levels, codes=[[], []], dtype=np.float64),
+            index=MultiIndex(levels=index.levels, codes=[[], []]),
             dtype=np.float64,
         )
         result = x.loc[empty]
@@ -129,7 +129,7 @@ def test_loc_getitem_array(self):
         empty = np.array([])
         expected = Series(
             [],
-            index=MultiIndex(levels=index.levels, codes=[[], []], dtype=np.float64),
+            index=MultiIndex(levels=index.levels, codes=[[], []]),
             dtype="float64",
         )
         result = x.loc[empty]