From 2452eee9dae0e06b45fb9b1782285b933a2ab774 Mon Sep 17 00:00:00 2001
From: Patrick Hoefler <61934744+phofl@users.noreply.github.com>
Date: Sun, 3 Sep 2023 16:33:36 +0200
Subject: [PATCH] REG: filter not respecting the order of labels

---
 doc/source/whatsnew/v2.1.1.rst            |  1 +
 pandas/core/generic.py                    |  8 +++++---
 pandas/tests/frame/methods/test_filter.py | 14 ++++++++++++++
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/doc/source/whatsnew/v2.1.1.rst b/doc/source/whatsnew/v2.1.1.rst
index 8b4833f6ce043..0eb7eb7cdd570 100644
--- a/doc/source/whatsnew/v2.1.1.rst
+++ b/doc/source/whatsnew/v2.1.1.rst
@@ -17,6 +17,7 @@ Fixed regressions
 - Fixed regression in :func:`read_csv` when ``usecols`` is given and ``dtypes`` is a dict for ``engine="python"`` (:issue:`54868`)
 - Fixed regression in :meth:`.GroupBy.get_group` raising for ``axis=1`` (:issue:`54858`)
 - Fixed regression in :meth:`DataFrame.__setitem__` raising ``AssertionError`` when setting a :class:`Series` with a partial :class:`MultiIndex` (:issue:`54875`)
+- Fixed regression in :meth:`DataFrame.filter` not respecting the order of elements for ``filter`` (:issue:`54980`)
 - Fixed regression in :meth:`Series.value_counts` raising for numeric data if ``bins`` was specified (:issue:`54857`)
 - Fixed regression when comparing a :class:`Series` with ``datetime64`` dtype with ``None`` (:issue:`54870`)
 
diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index b9407ebe6624a..6586a4f7f7015 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -5718,10 +5718,12 @@ def filter(
 
         if items is not None:
             name = self._get_axis_name(axis)
+            items = Index(items).intersection(labels)
+            if len(items) == 0:
+                # Keep the dtype of labels when we are empty
+                items = items.astype(labels.dtype)
             # error: Keywords must be strings
-            return self.reindex(  # type: ignore[misc]
-                **{name: labels.intersection(items)}
-            )
+            return self.reindex(**{name: items})  # type: ignore[misc]
         elif like:
 
             def f(x) -> bool_t:
diff --git a/pandas/tests/frame/methods/test_filter.py b/pandas/tests/frame/methods/test_filter.py
index 1a2fbf8a65a55..9d5e6876bb08c 100644
--- a/pandas/tests/frame/methods/test_filter.py
+++ b/pandas/tests/frame/methods/test_filter.py
@@ -137,3 +137,17 @@ def test_filter_regex_non_string(self):
         result = df.filter(regex="STRING")
         expected = df[["STRING"]]
         tm.assert_frame_equal(result, expected)
+
+    def test_filter_keep_order(self):
+        # GH#54980
+        df = DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
+        result = df.filter(items=["B", "A"])
+        expected = df[["B", "A"]]
+        tm.assert_frame_equal(result, expected)
+
+    def test_filter_different_dtype(self):
+        # GH#54980
+        df = DataFrame({1: [1, 2, 3], 2: [4, 5, 6]})
+        result = df.filter(items=["B", "A"])
+        expected = df[[]]
+        tm.assert_frame_equal(result, expected)