doc: reading via cfgrib

[raybellwaves]

In the docs http://xarray.pydata.org/en/stable/io.html#grib-format-via-cfgrib

Curious if eccodes is needed if reading a grib using using the cfgrib backend?

Does installing cfgrib via conda also install the binary dependencies?
https://github.com/ecmwf/cfgrib#installation

cc. @alexamici

[raybellwaves]

Looks as though it does

ray@ray-MS-7B43:~$ conda install -c conda-forge cfgrib
Collecting package metadata (current_repodata.json): done
Solving environment: done

## Package Plan ##

  environment location: /home/ray/local/bin/anaconda3/envs/rcclwx-dev

  added / updated specs:
    - cfgrib


The following packages will be downloaded:

    package                    |            build
    ---------------------------|-----------------
    cffi-1.14.0                |   py38he30daa8_1         225 KB
    cfgrib-0.9.8.2             |             py_0          42 KB  conda-forge
    eccodes-2.17.0             |       hf05d9b7_2         3.9 MB  conda-forge
    ------------------------------------------------------------
                                           Total:         4.2 MB

The following NEW packages will be INSTALLED:

  attrs              conda-forge/noarch::attrs-19.3.0-py_0
  cffi               pkgs/main/linux-64::cffi-1.14.0-py38he30daa8_1
  cfgrib             conda-forge/noarch::cfgrib-0.9.8.2-py_0
  eccodes            conda-forge/linux-64::eccodes-2.17.0-hf05d9b7_2
  jasper             conda-forge/linux-64::jasper-1.900.1-h07fcdf6_1006
  libaec             conda-forge/linux-64::libaec-1.0.4-he1b5a44_1
  pycparser          conda-forge/noarch::pycparser-2.20-py_0

May be able to drop the suggestion of installing eccodes from the docs.

[shoyer]

May be able to drop the suggestion of installing eccodes from the docs.

Agreed! conda install -c conda-forge cfgrib should be the recommended instructions -- no need to mention eccodes separately.