diff --git a/tests/test_partitioning.py b/tests/test_partitioning.py
index 3be173e91..04596cf4a 100644
--- a/tests/test_partitioning.py
+++ b/tests/test_partitioning.py
@@ -25,13 +25,9 @@ def generate_mesh_2d(nx, ny, name="mesh2d"):
 
 
 def generate_mesh_1d(n, name="mesh1d"):
-    points = [
-        (p,p) for p in np.linspace(0, n, n+1)
-    ]
-    connectivity = [
-        [it, it+1] for it in range(n)
-    ]
-    
+    points = [(p, p) for p in np.linspace(0, n, n + 1)]
+    connectivity = [[it, it + 1] for it in range(n)]
+
     return xu.Ugrid1d(*np.array(points).T, -1, np.array(connectivity), name=name)
 
 
@@ -232,12 +228,13 @@ def test_merge_partitions__errors(self):
         ):
             pt.merge_partitions([self.datasets[0], dataset3])
 
+
 class TestMergeDataset1D:
     @pytest.fixture(autouse=True)
     def setup(self):
         grid = generate_mesh_1d(6, "mesh1d")
         # TODO: If partitioning implemented for 1D grids, replace with that.
-        i_edges = [[0,1,2], [3,4,5]]
+        i_edges = [[0, 1, 2], [3, 4, 5]]
         parts = [grid.isel(mesh1d_nEdges=np.array(ls)) for ls in i_edges]
 
         values_parts = [np.arange(part.n_edge) for part in parts]
@@ -270,6 +267,7 @@ def test_merge_partitions(self):
         assert self.dataset_expected["a"].equals(merged["a"])
         assert self.dataset_expected.equals(merged)
 
+
 class TestMultiTopology1D2DMergePartitions:
     @pytest.fixture(autouse=True)
     def setup(self):
@@ -277,14 +275,16 @@ def setup(self):
         grid_b = generate_mesh_1d(6, "mesh1d")
         parts_a = grid_a.partition(n_part=2)
         # TODO: If partitioning implemented for 1D grids, replace with that.
-        i_edges = [[0,1,2], [3,4,5]]
+        i_edges = [[0, 1, 2], [3, 4, 5]]
         parts_b = [grid_b.isel(mesh1d_nEdges=np.array(ls)) for ls in i_edges]
 
-        values_parts_a = [np.arange(part.n_face) for part in parts_a] 
+        values_parts_a = [np.arange(part.n_face) for part in parts_a]
         values_parts_b = [np.arange(part.n_edge) for part in parts_b]
 
         datasets_parts = []
-        for i, (part_a, part_b, values_a, values_b) in enumerate(zip(parts_a, parts_b, values_parts_a, values_parts_b)):
+        for i, (part_a, part_b, values_a, values_b) in enumerate(
+            zip(parts_a, parts_b, values_parts_a, values_parts_b)
+        ):
             ds = xu.UgridDataset(grids=[part_a, part_b])
             ds["a"] = ((part_a.face_dimension), values_a)
             ds["b"] = ((part_b.edge_dimension), values_b)
@@ -296,7 +296,10 @@ def setup(self):
         ds_expected["b"] = ((grid_b.edge_dimension), np.concatenate(values_parts_b))
         ds_expected["c"] = 0
         # Assign coordinates also added during merge_partitions
-        coords = {grid_a.face_dimension: np.arange(grid_a.n_face), grid_b.edge_dimension: np.arange(grid_b.n_edge)}
+        coords = {
+            grid_a.face_dimension: np.arange(grid_a.n_face),
+            grid_b.edge_dimension: np.arange(grid_b.n_edge),
+        }
         ds_expected = ds_expected.assign_coords(**coords)
 
         self.datasets_parts = datasets_parts
@@ -309,4 +312,4 @@ def test_merge_partitions(self):
         # In case of non-UGRID data, it should default to the first partition:
         assert merged["c"] == 0
 
-        assert self.dataset_expected.equals(merged)
\ No newline at end of file
+        assert self.dataset_expected.equals(merged)