cfdm.Field.nc_hdf5_chunksizes

Field.nc_hdf5_chunksizes(todict=False)[source]

Get the HDF5 chunking strategy for the data.

New in version (cfdm): 1.11.2.0

See also

nc_clear_hdf5_chunksizes, nc_set_hdf5_chunksizes, cfdm.read, cfdm.write

Parameters
todict: bool, optional

If True then the HDF5 chunking strategy must comprise the maximum number of array elements in a chunk along each data axis, and these HDF chunk sizes are returned in a dict keyed by domain axis identities. If False (the default) then the HDF chunking strategy is returned with any of the return options other than a dict, as described below.

Returns
None or str or int or dict or tuple of int

The current chunking strategy when writing to a netCDF4 file. One of:

  • None: No HDF5 chunking strategy has been defined. The chunking strategy will be determined at write time by cfdm.write.

  • 'contiguous': The data will be written to the file contiguously, i.e. no chunking.

  • int or str: The size in bytes of the HDF5 chunks. A string represents a quantity of byte units. “Square-like” chunk shapes are preferred, maximising the amount of chunks that are completely filled with data values (see the cfdm.write hdf5_chunks parameter for details). For instance a chunksize of 1024 bytes may be specified with any of 1024, '1024', '1024 B', '1 KiB', '0.0009765625 MiB', etc. Recognised byte units are (case insensitive): B, KiB, MiB, GiB, TiB, PiB, KB, MB, GB, TB, and PB.

  • tuple of int: The maximum number of array elements in a chunk along each data axis. This chunking strategy may get automatically modified by methods that change the data shape (such as insert_dimension).

  • dict: If todict is True, the maximum number of array elements in a chunk along each axis. This chunking strategy may get automatically modified by methods that change the data shape (such as insert_dimension).