The cf package uses Dask for all of its array manipulation and can:

• read field constructs from netCDF, CDL, Zarr, PP and UM datasets with a choice of netCDF backends,and in local, http, and s3 locations,
• create new field constructs in memory,
• write and append field and domain constructs to netCDF and Zarr v3 datasets on disk, with control over HDF5 internal file metadata,
• read, create, and manipulate UGRID mesh topologies,
• read, write, and create coordinates defined by geometry cells,
• read netCDF and CDL datasets containing hierarchical groups,
• inspect field constructs,
• test whether two field constructs are the same,
• modify field construct metadata and data,
• create subspaces of field constructs,
• incorporate, and create, metadata stored in external files,
• read, write, and create data that have been compressed by convention (i.e. ragged or gathered arrays, or coordinate arrays compressed by subsampling), whilst presenting a view of the data in its uncompressed form,
• combine field constructs arithmetically,
• manipulate field construct data by arithmetical and trigonometrical operations,
• perform weighted statistical collapses on field constructs, including those with geometry cells and UGRID mesh topologies,
• perform histogram, percentile and binning operations on field constructs,
• regrid structured grid, mesh and DSG field constructs with (multi-)linear, nearest neighbour, first- and second-order conservative and higher order patch recovery methods, including 3-d regridding, and large-grid support,
• apply convolution filters to field constructs,
• create running means from field constructs,
• apply differential operators to field constructs,
• create derived quantities (such as relative vorticity).
• read and write data that are quantized to eliminate false precision.

Powerful and flexible visualizations of cf field constructs, designed to be produced and configured in as few lines of code as possible, are available with the cf-plot package, which needs to be installed separately to the cf package.

During installation the cfa command line utility is also installed, which

• generates text descriptions of field constructs contained in files, and

• creates new datasets aggregated from existing files.

Tests are run from within the cf/test directory:

Training material on cf-python and cf-plot i.e. the CF Data Tools, in the form of Jupyter Notebooks, is openly-accessible and available (with instructions for set-up provided) at: https://github.com/NCAS-CMS/cf-tools-training.