Apply ruff/refurb preview rule FURB171

FURB171 Membership test against single-item container
pydata · max-sixty · Jun 30, 2025 · Jun 29, 2025 · Jun 29, 2025 · Jun 29, 2025
commit b5d8bfa50cf6311331cb5e684dff63a85bfdaa4d
diff --git a/xarray/backends/zarr.py b/xarray/backends/zarr.py
@@ -1545,7 +1545,7 @@ def guess_can_open(
     ) -> bool:
         if isinstance(filename_or_obj, str | os.PathLike):
             _, ext = os.path.splitext(filename_or_obj)
-            return ext in {".zarr"}
+            return ext == ".zarr"
 
         return False
 

diff --git a/xarray/computation/nanops.py b/xarray/computation/nanops.py
@@ -112,7 +112,7 @@ def _nanmean_ddof_object(ddof, value, axis=None, dtype=None, **kwargs):
     # As dtype inference is impossible for object dtype, we assume float
     # https://github.com/dask/dask/issues/3162
     if dtype is None and value.dtype.kind == "O":
-        dtype = value.dtype if value.dtype.kind in ["cf"] else float
+        dtype = value.dtype if value.dtype.kind == "cf" else float
 
     data = np.sum(value, axis=axis, dtype=dtype, **kwargs)
     data = data / (valid_count - ddof)

diff --git a/xarray/tests/test_dataarray.py b/xarray/tests/test_dataarray.py
@@ -2920,7 +2920,7 @@ def test_reduce_keepdims(self) -> None:
         expected = DataArray(
             orig.data.mean(keepdims=True),
             dims=orig.dims,
-            coords={k: v for k, v in coords.items() if k in ["c"]},
+            coords={k: v for k, v in coords.items() if k == "c"},
         )
         assert_equal(actual, expected)
 

diff --git a/xarray/tests/test_duck_array_ops.py b/xarray/tests/test_duck_array_ops.py
@@ -587,7 +587,7 @@ def test_reduce(dim_num, dtype, dask, func, skipna, aggdim):
     if dask and not has_dask:
         pytest.skip("requires dask")
 
-    if dask and skipna is False and dtype in [np.bool_]:
+    if dask and skipna is False and dtype == np.bool_:
         pytest.skip("dask does not compute object-typed array")
 
     rtol = 1e-04 if dtype == np.float32 else 1e-05

diff --git a/xarray/tests/test_interp.py b/xarray/tests/test_interp.py
@@ -124,7 +124,7 @@ def test_interpolate_1d(method: InterpOptions, dim: str, case: int) -> None:
     if not has_scipy:
         pytest.skip("scipy is not installed.")
 
-    if not has_dask and case in [1]:
+    if not has_dask and case == 1:
         pytest.skip("dask is not installed in the environment.")
 
     da = get_example_data(case)
@@ -433,7 +433,7 @@ def test_interpolate_nd_with_nan() -> None:
     "case", [pytest.param(0, id="no_chunk"), pytest.param(1, id="chunk_y")]
 )
 def test_interpolate_scalar(method: InterpOptions, case: int) -> None:
-    if not has_dask and case in [1]:
+    if not has_dask and case == 1:
         pytest.skip("dask is not installed in the environment.")
 
     da = get_example_data(case)
@@ -463,7 +463,7 @@ def func(obj, new_x):
     "case", [pytest.param(3, id="no_chunk"), pytest.param(4, id="chunked")]
 )
 def test_interpolate_nd_scalar(method: InterpOptions, case: int) -> None:
-    if not has_dask and case in [4]:
+    if not has_dask and case == 4:
         pytest.skip("dask is not installed in the environment.")
 
     da = get_example_data(case)

diff --git a/xarray/tests/test_rolling.py b/xarray/tests/test_rolling.py
@@ -341,7 +341,7 @@ def test_ndrolling_reduce(
         assert_allclose(actual, expected)
         assert actual.sizes == expected.sizes
 
-        if name in ["mean"]:
+        if name == "mean":
             # test our reimplementation of nanmean using np.nanmean
             expected = getattr(rolling_obj.construct({"time": "tw", "x": "xw"}), name)(
                 ["tw", "xw"]