Added datatree leading slash to encoding

Author: norlandrhagen

src/topozarr/coarsen.py

@@ -60,8 +60,9 @@ def create_pyramid(
         if "spatial_ref" in ds_level.coords:
             ds_level = ds_level.drop_vars("spatial_ref")
 
-        path = str(idx)
-        dt[path] = DataTree(ds_level, name=path)
+        name = str(idx)
+        path = f"/{idx}"
+        dt[path] = DataTree(ds_level, name=name)
         full_encoding[path] = create_level_encoding(
             ds_level,
             x_dim,

tests/test_chunking.py

@@ -32,8 +32,8 @@ def test_chunk_size_overrides(create_dataset):
     pyramid_small = create_pyramid(ds, levels=1, target_chunk_bytes=1024)
     pyramid_large = create_pyramid(ds, levels=1, target_chunk_bytes=10 * 1024 * 1024)
 
-    chunk_small = pyramid_small.encoding["0"]["elevation"]["chunks"]
-    chunk_large = pyramid_large.encoding["0"]["elevation"]["chunks"]
+    chunk_small = pyramid_small.encoding["/0"]["elevation"]["chunks"]
+    chunk_large = pyramid_large.encoding["/0"]["elevation"]["chunks"]
 
     assert chunk_small[0] < chunk_large[0]
 
@@ -48,5 +48,5 @@ def test_shard_size_overrides(create_dataset):
         ds, levels=1, target_chunk_bytes=target, target_shard_bytes=target
     )
 
-    enc = pyramid.encoding["0"]["elevation"]
+    enc = pyramid.encoding["/0"]["elevation"]
     assert enc["chunks"] == enc["shards"]

tests/test_specs.py

@@ -44,7 +44,7 @@ def test_encoding_contains_shards(create_dataset):
     ds = create_dataset(nx=1000, ny=1000)
     pyramid = create_pyramid(ds, levels=1)
 
-    enc = pyramid.encoding["0"]["elevation"]
+    enc = pyramid.encoding["/0"]["elevation"]
     assert "chunks" in enc
     assert "shards" in enc
     assert all(shard >= chunk for shard, chunk in zip(enc["shards"], enc["chunks"]))