add encodings["preferred_chunks"], used in open_dataset instead of en… (

pydata#4669) * add encodings["preferred_chunks"], used in open_dataset instead of encodings["chunks"] * modify preferred_chunks: now it's a dictionary not a list * fix if preferred_chunks is not defined
centurylee · Dec 17, 2020 · 91318d2 · 91318d2
1 parent 778a16e
commit 91318d2
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Showing 2 changed files with 5 additions and 2 deletions.
diff --git a/xarray/backends/zarr.py b/xarray/backends/zarr.py
@@ -312,6 +312,7 @@ def open_store_variable(self, name, zarr_array):
         attributes = dict(attributes)
         encoding = {
             "chunks": zarr_array.chunks,
+            "preferred_chunks": dict(zip(dimensions, zarr_array.chunks)),
             "compressor": zarr_array.compressor,
             "filters": zarr_array.filters,
         }

diff --git a/xarray/core/dataset.py b/xarray/core/dataset.py
@@ -389,8 +389,10 @@ def _get_chunk(var, chunks):
     if isinstance(chunks, int) or (chunks == "auto"):
         chunks = dict.fromkeys(var.dims, chunks)
 
-    preferred_chunks_list = var.encoding.get("chunks", {})
-    preferred_chunks = dict(zip(var.dims, var.encoding.get("chunks", {})))
+    preferred_chunks = var.encoding.get("preferred_chunks", {})
+    preferred_chunks_list = [
+        preferred_chunks.get(dim, shape) for dim, shape in zip(var.dims, var.shape)
+    ]
 
     chunks_list = [
         chunks.get(dim, None) or preferred_chunks.get(dim, None) for dim in var.dims