fix: data tests on macos

test/test_data.py

@@ -9,6 +9,16 @@
 from torch.utils.data import DataLoader, IterableDataset
 
 
+class _Unzip(IterableDataset):
+    def __init__(self, ds):
+        self.ds = ds
+
+    def __iter__(self):
+        for chunk in self.ds:
+            arr = chunk.to_array().values[0]
+            yield from arr
+
+
 class TestSharding:
     def test_types(self):
         indices = shard_indices(10, 0, 2, shuffle=False, drop_remainder=False)
@@ -94,15 +104,6 @@ def test_shuffled(self):
         assert chunk.tolist() == list(range(chunk[0], chunk[-1] + 1))
 
     def test_XrShardedDataset_multiprocessing(self):
-        class _Unzip(IterableDataset):
-            def __init__(self, ds):
-                self.ds = ds
-
-            def __iter__(self):
-                for chunk in self.ds:
-                    arr = chunk.to_array().values[0]
-                    yield from arr
-
         xr_ds = xr.DataArray(np.arange(100), dims=['x'], name='var').to_dataset()
 
         # Simple case: 2 workers, world_size=1