From 84aac6d1c79b833fdab17be672029616507a5f23 Mon Sep 17 00:00:00 2001
From: Illviljan <14371165+Illviljan@users.noreply.github.com>
Date: Sat, 21 Oct 2023 22:32:41 +0200
Subject: [PATCH 1/2] Tuple loop is not needed

---
 xarray/core/variable.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xarray/core/variable.py b/xarray/core/variable.py
index 4ad723325d3..26dcb5472d5 100644
--- a/xarray/core/variable.py
+++ b/xarray/core/variable.py
@@ -2193,7 +2193,7 @@ def rolling_window(
                 pads[d] = (win - 1, 0)
 
         padded = var.pad(pads, mode="constant", constant_values=fill_value)
-        axis = tuple(self.get_axis_num(d) for d in dim)
+        axis = self.get_axis_num(dim)
         new_dims = self.dims + tuple(window_dim)
         return Variable(
             new_dims,

From 29bdfa78325f1d7e2545fc5424da99a9b30e3d53 Mon Sep 17 00:00:00 2001
From: Illviljan <14371165+Illviljan@users.noreply.github.com>
Date: Sat, 21 Oct 2023 22:37:10 +0200
Subject: [PATCH 2/2] dims are usually tuple[Hashable, ...]

---
 xarray/core/variable.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xarray/core/variable.py b/xarray/core/variable.py
index 26dcb5472d5..9601ad49d05 100644
--- a/xarray/core/variable.py
+++ b/xarray/core/variable.py
@@ -2162,7 +2162,7 @@ def rolling_window(
                     raise ValueError(
                         f"Expected {name}={arg!r} to be a scalar like 'dim'."
                     )
-            dim = [dim]
+            dim = (dim,)
 
         # dim is now a list
         nroll = len(dim)