Compress a file using the Command Line Interface

An example on how to compress a netcdf file using enstools-compression’s CLI.

Prepare something to compress

[1]:

import xarray
from pathlib import Path
from enstools.io import write, read

WARNING: eccodes c-library not found, grib file support not available!

[2]:

dataset_name = "air_temperature"
dataset = xarray.tutorial.open_dataset(dataset_name)

[3]:

# Define a path for the temporary file
input_file = Path("input.nc")
output_file = Path("compressed.nc")

[4]:

# Save dataset to a netcdf file
write(dataset, input_file)

/home/docs/checkouts/readthedocs.org/user_builds/enstools-compression/envs/latest/lib/python3.8/site-packages/enstools/io/writer.py:146: SerializationWarning: saving variable air with floating point data as an integer dtype without any _FillValue to use for NaNs
  task = ds.to_netcdf(file_path, engine=engine, encoding=dataset_encoding, compute=compute, format=format)

Compress the file

[5]:

! enstools-compression compress "input.nc" -o "compressed.nc" --compression 'lossy,sz,abs,0.14'

WARNING: eccodes c-library not found, grib file support not available!

Open compressed file and check that the content can be read

[6]:

with read("compressed.nc") as ds:
    print(ds.values)

<bound method Mapping.values of <xarray.Dataset>
Dimensions:  (lat: 25, time: 2920, lon: 53)
Coordinates:
  * lat      (lat) float32 75.0 72.5 70.0 67.5 65.0 ... 25.0 22.5 20.0 17.5 15.0
  * lon      (lon) float32 200.0 202.5 205.0 207.5 ... 322.5 325.0 327.5 330.0
  * time     (time) datetime64[ns] 2013-01-01 ... 2014-12-31T18:00:00
Data variables:
    air      (time, lat, lon) float32 dask.array<chunksize=(2920, 25, 53), meta=np.ndarray>
Attributes:
    Conventions:  COARDS
    title:        4x daily NMC reanalysis (1948)
    description:  Data is from NMC initialized reanalysis\n(4x/day).  These a...
    platform:     Model
    references:   http://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanaly...>

Remove Temporary files

[7]:

# Remove files
if input_file.exists():
    input_file.unlink()
if output_file.exists():
    output_file.unlink()