Metadata-Version: 1.1
Name: cfgrib
Version: 0.8.4.4
Summary: Python interface to map GRIB files to the NetCDF Common Data Model following the CF Convention using ecCodes.
Home-page: https://github.com/ecmwf/cfgrib
Author: European Centre for Medium-Range Weather Forecasts (ECMWF)
Author-email: software.support@ecmwf.int
License: Apache License Version 2.0
Description: 
        Python interface to map GRIB files to the
        `NetCDF Common Data Model <https://www.unidata.ucar.edu/software/thredds/current/netcdf-java/CDM/>`_
        following the `CF Conventions <http://cfconventions.org/>`_.
        The high level API is designed to support a GRIB backend for `xarray <http://xarray.pydata.org/>`_
        and it is inspired by `NetCDF-python <http://unidata.github.io/netcdf4-python/>`_
        and `h5netcdf <https://github.com/shoyer/h5netcdf>`_.
        Low level access and decoding is performed via the
        `ECMWF ecCodes library <https://software.ecmwf.int/wiki/display/ECC/>`_.
        
        Features:
        
        - provisional GRIB driver for *xarray*,
        - support all modern versions of Python 3.7, 3.6, 3.5 and 2.7, plus PyPy and PyPy3,
        - only system dependency is the ecCodes C-library (not the Python2-only module),
        - no install time build (binds with *CFFI* ABI mode),
        - read the data lazily and efficiently in terms of both memory usage and disk access,
        - map a GRIB 1 or 2 file to a set of N-dimensional variables following the NetCDF Common Data Model,
        - add CF Conventions attributes to known coordinate and data variables.
        
        Limitations:
        
        - development stage: **Alpha**,
        - limited support for multi-variable GRIB files (yet),
          see `#2 <https://github.com/ecmwf/cfgrib/issues/2>`_,
          `#13 <https://github.com/ecmwf/cfgrib/issues/13>`_ and the Advanced Usage section below,
        - no write support (yet),
        - no support for opening multiple GRIB files (yet),
        - incomplete documentation (yet),
        - no Windows support, see `#7 <https://github.com/ecmwf/cfgrib/issues/7>`_,
        - rely on *ecCodes* for the CF attributes of the data variables,
        - rely on *ecCodes* for the ``gridType`` handling.
        
        
        Installation
        ------------
        
        The package is installed from PyPI with::
        
            $ pip install cfgrib
        
        
        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
        
        As an alternative you may install the official source distribution
        by following the instructions at
        https://software.ecmwf.int/wiki/display/ECC/ecCodes+installation
        
        Note that *ecCodes* support for the Windows operating system is experimental.
        
        You may run a simple selfcheck command to ensure that your system is set up correctly::
        
            $ python -m cfgrib selfcheck
            Found: ecCodes v2.7.0.
            Your system is ready.
        
        
        Usage
        -----
        
        First, you need a well-formed GRIB file, if you don't have one at hand you can download our
        `ERA5 on pressure levels sample <http://download.ecmwf.int/test-data/cfgrib/era5-levels-members.grib>`_::
        
            $ wget http://download.ecmwf.int/test-data/cfgrib/era5-levels-members.grib
        
        
        Dataset / Variable API
        ~~~~~~~~~~~~~~~~~~~~~~
        
        You may try out the high level API in a python interpreter:
        
        .. code-block: python
        
        >>> import cfgrib
        >>> ds = cfgrib.Dataset.frompath('era5-levels-members.grib')
        >>> ds.attributes['GRIB_edition']
        1
        >>> sorted(ds.dimensions.items())
        [('air_pressure', 2), ('latitude', 61), ('longitude', 120), ('number', 10), ('time', 4)]
        >>> sorted(ds.variables)
        ['air_pressure', 'latitude', 'longitude', 'number', 'step', 't', 'time', 'valid_time', 'z']
        >>> var = ds.variables['t']
        >>> var.dimensions
        ('number', 'time', 'air_pressure', 'latitude', 'longitude')
        >>> var.data[:, :, :, :, :].mean()
        262.92133
        
        
        Provisional *xarray* GRIB driver
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        
        If you have xarray installed ``cfgrib`` can open a GRIB file as a ``xarray.Dataset``::
        
            $ pip install xarray
        
        In a Python interpreter try:
        
        .. code-block: python
        
        >>> from cfgrib import xarray_store
        >>> ds = xarray_store.open_dataset('era5-levels-members.grib')
        >>> ds
        <xarray.Dataset>
        Dimensions:       (air_pressure: 2, latitude: 61, longitude: 120, number: 10, time: 4)
        Coordinates:
          * number        (number) int64 0 1 2 3 4 5 6 7 8 9
          * time          (time) datetime64[ns] 2017-01-01 2017-01-01T12:00:00 ...
            step          timedelta64[ns] ...
          * air_pressure  (air_pressure) float64 850.0 500.0
          * latitude      (latitude) float64 90.0 87.0 84.0 81.0 78.0 75.0 72.0 69.0 ...
          * longitude     (longitude) float64 0.0 3.0 6.0 9.0 12.0 15.0 18.0 21.0 ...
            valid_time    (time) datetime64[ns] ...
        Data variables:
            z             (number, time, air_pressure, latitude, longitude) float32 ...
            t             (number, time, air_pressure, latitude, longitude) float32 ...
        Attributes:
            GRIB_edition:            1
            GRIB_centre:             ecmf
            GRIB_centreDescription:  European Centre for Medium-Range Weather Forecasts
            GRIB_subCentre:          0
            history:                 GRIB to CDM+CF via cfgrib-0.8.../ecCodes-2...
        
        
        Lower level APIs
        ~~~~~~~~~~~~~~~~
        
        Lower level APIs are not stable and should not be considered public yet.
        In particular the internal Python 3 *ecCodes* bindings are not compatible with
        the standard *ecCodes* python module.
        
        
        Advanced usage
        --------------
        
        ``cfgrib.Dataset`` can open a GRIB file only if all the messages
        with the same ``shortName`` can be represented as a single ``cfgrib.Variable`` hypercube.
        For example, a variable ``t`` cannot have both ``isobaricInhPa`` and ``hybrid`` ``typeOfLevel``'s,
        as this would result in multiple hypercubes for variable ``t``.
        Opening a non-conformant GRIB file will fail with a ``ValueError: multiple values for unique attribute...``
        error message, see `#2 <https://github.com/ecmwf/cfgrib/issues/2>`_.
        
        Furthermore if different ``cfgrib.Variable``'s depend on the same coordinate,
        the values of the coordinate must match exactly.
        For example, if variables ``t`` and ``z`` share the same step coordinate,
        they must both have exactly the same set of steps.
        Opening a non-conformant GRIB file will fail with a ``ValueError: key present and new value is different...``
        error message, see `#13 <https://github.com/ecmwf/cfgrib/issues/13>`_.
        
        In most cases you can handle complex GRIB files containing heterogeneous messages by using
        the ``filter_by_keys`` keyword to select which GRIB messages belong to a
        well formed set of hypercubes.
        
        For example to open
        `US National Weather Service complex GRIB2 files <http://ftpprd.ncep.noaa.gov/data/nccf/com/nam/prod/>`_
        you can use:
        
        .. code-block: python
        
        >>> from cfgrib.xarray_store import open_dataset
        >>> open_dataset('nam.t00z.awip1200.tm00.grib2',
        ...              filter_by_keys={'typeOfLevel': 'surface', 'stepType': 'instant'})
        <xarray.Dataset>
        Dimensions:     (x: 614, y: 428)
        Coordinates:
            time        datetime64[ns] ...
            step        timedelta64[ns] ...
            surface     int64 ...
            latitude    (y, x) float64 ...
            longitude   (y, x) float64 ...
            valid_time  datetime64[ns] ...
        Dimensions without coordinates: x, y
        Data variables:
            vis         (y, x) float32 ...
            gust        (y, x) float32 ...
            hindex      (y, x) float32 ...
            sp          (y, x) float32 ...
            orog        (y, x) float32 ...
            t           (y, x) float32 ...
            unknown     (y, x) float32 ...
            sdwe        (y, x) float32 ...
            sde         (y, x) float32 ...
            prate       (y, x) float32 ...
            sr          (y, x) float32 ...
            veg         (y, x) float32 ...
            slt         (y, x) float32 ...
            lsm         (y, x) float32 ...
            ci          (y, x) float32 ...
            al          (y, x) float32 ...
            sst         (y, x) float32 ...
            shtfl       (y, x) float32 ...
            lhtfl       (y, x) float32 ...
        Attributes:
            GRIB_edition:            2
            GRIB_centre:             kwbc
            GRIB_centreDescription:  US National Weather Service - NCEP...
            GRIB_subCentre:          0
            history:                 GRIB to CDM+CF via cfgrib-0.8.../ecCodes-2...
        >>> open_dataset('nam.t00z.awip1200.tm00.grib2',
        ...              filter_by_keys={'typeOfLevel': 'heightAboveGround', 'topLevel': 2})
        <xarray.Dataset>
        Dimensions:            (x: 614, y: 428)
        Coordinates:
            time               datetime64[ns] ...
            step               timedelta64[ns] ...
            heightAboveGround  int64 ...
            latitude           (y, x) float64 ...
            longitude          (y, x) float64 ...
            valid_time         datetime64[ns] ...
        Dimensions without coordinates: x, y
        Data variables:
            t2m                (y, x) float32 ...
            q                  (y, x) float32 ...
            d2m                (y, x) float32 ...
            r2                 (y, x) float32 ...
        Attributes:
            GRIB_edition:            2
            GRIB_centre:             kwbc
            GRIB_centreDescription:  US National Weather Service - NCEP...
            GRIB_subCentre:          0
            history:                 GRIB to CDM+CF via cfgrib-0.8.../ecCodes-2...
        
        
        Contributing
        ------------
        
        The main repository is hosted on GitHub,
        testing, bug reports and contributions are highly welcomed and appreciated:
        
        https://github.com/ecmwf/cfgrib
        
        Please see the CONTRIBUTING.rst document for the best way to help.
        
        Lead developer:
        
        - `Alessandro Amici <https://github.com/alexamici>`_ - B-Open
        
        Main contributors:
        
        - Baudouin Raoult - ECMWF
        - `Aureliana Barghini <https://github.com/aurghs>`_ - B-Open
        - `Iain Russell <https://github.com/iainrussell>`_ - ECMWF
        - `Leonardo Barcaroli <https://github.com/leophys>`_ - B-Open
        
        See also the list of `contributors <https://github.com/ecmwf/cfgrib/contributors>`_ who participated in this project.
        
        
        License
        -------
        
        Copyright 2017-2018 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.
        
Keywords: eccodes grib
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: Operating System :: OS Independent
