fix: Fix encoding in 'to_zarr' to remove 'preferred_chunks' before sa…

…ving (#1128)

* Encoding and Chunk matching only if DaskArray

* Removing preffered chunks from encoding dict

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

echopype/utils/coding.py

@@ -208,6 +208,9 @@ def set_zarr_encodings(
                 chunks = _get_auto_chunk(val, chunk_size=chunk_size)
 
             encoding[name]["chunks"] = chunks
+        if PREFERRED_CHUNKS in encoding[name]:
+            # Remove 'preferred_chunks', use chunks only instead
+            encoding[name].pop(PREFERRED_CHUNKS)
 
     return encoding
 

echopype/utils/io.py

@@ -11,6 +11,7 @@
 
 import fsspec
 import xarray as xr
+from dask.array import Array as DaskArray
 from fsspec import FSMap
 from fsspec.implementations.local import LocalFileSystem
 
@@ -61,7 +62,8 @@ def save_file(ds, path, mode, engine, group=None, compression_settings=None, **k
     elif engine == "zarr":
         # Ensure that encoding and chunks match
         for var, enc in encoding.items():
-            ds[var] = ds[var].chunk(enc.get("chunks", {}))
+            if isinstance(ds[var].data, DaskArray):
+                ds[var] = ds[var].chunk(enc.get("chunks", {}))
         ds.to_zarr(store=path, mode=mode, group=group, encoding=encoding, **kwargs)
     else:
         raise ValueError(f"{engine} is not a supported save format")