Use netcdf4 as default engine

src/rechunk_data/__init__.py

@@ -10,7 +10,7 @@ from ._rechunk import (
     logger,
 )
 
-__version__ = "2208.0.1"
+__version__ = "2301.0.0"
 PROGRAM_NAME = "rechunk-data"
 
 
@@ -48,7 +48,7 @@ def parse_args(argv: Optional[List[str]]) -> argparse.Namespace:
         "--netcdf-engine",
         help=("The netcdf engine used to create the new netcdf file."),
         choices=("h5netcdf", "netcdf4"),
-        default="h5netcdf",
+        default="netcdf4",
         type=str,
     )
     parser.add_argument(

src/rechunk_data/_rechunk.py

@@ -118,12 +118,13 @@ def _rechunk_dataset(
         encoding[data_var] = {
             str(k): v for k, v in dset[var].encoding.items() if str(k) in _keywords
         }
-        encoding[data_var]["chunksizes"] = new_chunks
+        if engine != "netcdf4" or encoding[data_var].get("contiguous", False) is False:
+            encoding[data_var]["chunksizes"] = new_chunks
     return dset, encoding
 
 
 def rechunk_dataset(
-    dset: xr.Dataset, engine: Literal["h5netcdf", "netcdf4"] = "h5netcdf"
+    dset: xr.Dataset, engine: Literal["h5netcdf", "netcdf4"] = "netcdf4"
 ) -> xr.Dataset:
     """Rechunk a xarray dataset.
 
@@ -131,7 +132,7 @@ def rechunk_dataset(
     ----------
     dset: xarray.Dataset
         Input dataset that is going to be rechunked
-    engine: str, default: h5netcdf
+    engine: str, default: netcdf4
         The netcdf engine used to create the new netcdf file.
 
     Returns
@@ -145,7 +146,7 @@ def rechunk_dataset(
 def rechunk_netcdf_file(
     input_path: os.PathLike,
     output_path: Optional[os.PathLike] = None,
-    engine: Literal["h5netcdf", "netcdf4"] = "h5netcdf",
+    engine: Literal["h5netcdf", "netcdf4"] = "netcdf4",
 ) -> None:
     """Rechunk netcdf files.
 
@@ -158,7 +159,7 @@ def rechunk_netcdf_file(
         Output file/directory of the chunked netcdf file(s). Note: If ``input``
         is a directory output should be a directory. If None given (default)
         the ``input`` is overidden.
-    engine: str, default: h5netcdf
+    engine: str, default: netcdf4
         The netcdf engine used to create the new netcdf file.
     """
     input_path = Path(input_path).expanduser().absolute()
@@ -173,16 +174,21 @@ def rechunk_netcdf_file(
             output_file = Path(output_path)
         output_file.parent.mkdir(exist_ok=True, parents=True)
         try:
-            with xr.open_mfdataset(str(input_file), parallel=True) as nc_data:
+            with xr.open_mfdataset(
+                str(input_file), decode_cf=True, parallel=True
+            ) as nc_data:
                 new_data, encoding = _rechunk_dataset(nc_data, engine)
                 if encoding:
                     logger.debug(
-                        "Loading data into memory (%s).", format_bytes(new_data.nbytes)
+                        "Loading data into memory (%s).",
+                        format_bytes(new_data.nbytes),
                     )
                     new_data = new_data.load()
         except Exception as error:
             logger.error(
-                "Error while processing file %s: %s", str(input_file), str(error)
+                "Error while processing file %s: %s",
+                str(input_file),
+                str(error),
             )
             continue
         _save_dataset(