Skip to content

Latest commit

 

History

History
134 lines (89 loc) · 4.47 KB

README.rst

File metadata and controls

134 lines (89 loc) · 4.47 KB
Raw

Python 3 interface to encode and decode GRIB and BUFR files via the ECMWF ecCodes library.

Features with development status Beta:

  • reads and writes GRIB 1 and 2 files,
  • reads and writes BUFR 3 and 4 files,
  • supports all modern versions of Python 3.7, 3.6, 3.5 and PyPy3,
  • works on most Linux distributions and MacOS, the ecCodes C-library is the only system dependency,
  • PyPI package with no install time build (binds with CFFI ABI level, in-line mode),
  • supports writing the index of a GRIB file to disk, to save a full-file scan on open.

Limitations:

  • CFFI ABI level, in-line mode is almost twice as slow as the original ecCodes bindings,
  • only experimental support for the much faster CFFI API level, out-of-line mode,
  • PyPI binary packages do not include ecCodes,
  • incomplete documentation, for now,
  • no Windows support, for now.

Installation

The package is installed from PyPI with:

$ pip install eccodes-python

System dependencies

The Python module depends on the ECMWF ecCodes library that must be installed on the system and accessible as a shared library. Some Linux distributions ship a binary version that may be installed with the standard package manager. On Ubuntu 18.04 use the command:

$ sudo apt-get install libeccodes0

On a MacOS with HomeBrew use:

$ brew install eccodes

Or if you manage binary packages with Conda use:

$ conda install -c conda-forge eccodes

As an alternative you may install the official source distribution by following the instructions at https://software.ecmwf.int/wiki/display/ECC/ecCodes+installation

You may run a simple selfcheck command to ensure that your system is set up correctly:

$ python -m eccodes selfcheck
Found: ecCodes v2.7.0.
Your system is ready.

Usage

Refer to the ecCodes documentation pages for usage.

Experimental features

Fast bindings

To test the much faster CFFI API level, out-of-line mode you need the ecCodes source tree available, because we need two include files grib_api_internal.h and grib_api_prototypes.h that are not installed by default. Then you need to clone the repo in the same folder as your ecCodes source tree, make a pip development install and custom compile the binary bindings:

$ git clone https://github.com/ecmwf/eccodes-python
$ cd eccodes-python
$ pip install -e .
$ CPPFLAGS=-I../eccodes/src python builder.py

To revert back to ABI level, in-line more just remove the compiled bindings:

$ rm gribapi/_bindings.*

Project resources

Development https://github.com/ecmwf/eccodes-python
Download https://pypi.org/project/eccodes-python

Code quality

Build Status on Travis CI

Coverage Status on Coveralls

Contributing

The main repository is hosted on GitHub, testing, bug reports and contributions are highly welcomed and appreciated:

https://github.com/ecmwf/eccodes-python

Please see the CONTRIBUTING.rst document for the best way to help.

Lead developer:

See also the list of contributors who participated in this project.

License

Copyright 2017-2019 European Centre for Medium-Range Weather Forecasts (ECMWF).

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.