Installation

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Version 3.0.0 for version 1.7 of the CF conventions.

Operating systems

cf works only for Linux and Mac operating systems.

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Python versions

cf works only for Python 3.5 or later. (Versions 2.x of cf work only for Python 2.7.)

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conda

cf-python is in the ncas conda channel. To install cf with all of its required and optional dependencies, and the cf-plot visualisation package, run

Install with conda.

conda install -c ncas -c conda-forge cf-python cf-plot udunits2
conda install -c conda-forge mpich esmpy

The second of the two conda commands is required for regridding to work.

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pip

cf-python is in the Python package index: https://pypi.org/project/cf-python

To install cf and all of its required dependencies run, for example:

Install as root, with any missing dependencies.

pip install cf-python

Install as a user, with any missing dependencies.

pip install cf-python --user

To install cf without any of its dependencies then run, for example:

Install as root without installing any of the dependencies.

pip install cf-python --no-deps

See the documentation for pip install for further options.

The optional dependencies are not automatically installed via pip.

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Source

To install from source:

1. Download the cf-python package from https://pypi.org/project/cf-python

2. Unpack the library (replacing <version> with the version that you want to install, e.g. 3.0.0):

   tar zxvf cf-python-<version>.tar.gz
   cd cf-python-<version>
   

3. Install the package:

• To install the cf-python package to a central location:

  python setup.py install
  

• To install the cf-python package locally to the user in the default location:

  python setup.py install --user
  

• To install the cf-python package in the <directory> of your choice:

  python setup.py install --home=<directory>
  

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cfa utility

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.

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Tests

Tests are run from within the cf-python/test directory:

python run_tests.py

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Dependencies

Required

• Python, version 3 or newer.

• numpy, version 1.15 or newer.

• netCDF4, version 1.4.0 or newer.

• cftime, version 1.0.2 or newer. (Note that this package is installed with netCDF4.)

• cfdm, version 1.7.7 or newer.

• cfunits, version 3.2.2 or newer.

• psutil, version 0.6.0 or newer.

• UNIDATA UDUNITS-2 library, version 2.2.20 or newer.

  This is a C library which provides support for units of physical quantities. If the UDUNITS-2 shared library file (libudunits2.so.0 on GNU/Linux or libudunits2.0.dylibfile on MacOS) is in a non-standard location then its path should be added to the LD_LIBRARY_PATH environment variable. It may also be necessary to specify the location of the udunits2.xml file in the UDUNITS2_XML_PATH environment variable (although the default location is usually correct).

Optional

Some further dependencies that, enable further functionality, are optional. This to faciliate cf-python being installed in restricted environments:

Regridding

• ESMF, version 7.1.0r or newer. This is easily installed via conda with

  conda install -c conda-forge mpich esmpy
  

  or may be installed from source.

Convolution filters, derivatives and relative vorticity

• scipy, version 1.3.0 or newer.

Subspacing based on N-d construct cells (N > 1) containing a given value

• matplotlib, version 3.0.0 or newer.

Parallel processing

• mpi4py

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Code repository

The complete source code is available at https://github.com/NCAS-CMS/cf-python