netcdf info

netcdf info#

Information on a netcdf file

This module was written by Matthias Cuntz while at Department of Computational Hydrosystems, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany, and continued while at Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Nancy, France.

copyright:

Copyright 2009-2023 Matthias Cuntz, Stephan Thober, see AUTHORS.rst for details.

license:

MIT License, see LICENSE for details.

The following functions are provided

ncinfo(ncfile[, var, code, variables, ...])

Get information on variables in a netcdf file

infonetcdf(*args, **kwargs)

Wrapper for ncinfo()
History

  • Written Mar 2022 from ncread by moving all info abilities into separate routine infonetcdf with wrapper function ncinfo, Mar 2022, Matthias Cuntz

  • Invert functions and wrapper functions, Feb 2023, Matthias Cuntz

  • Move ncinfo in separate file, Nov 2023, Matthias Cuntz

  • sort=True default, Nov 2023, Matthias Cuntz

  • Enforce keywords after var, Nov 2023, Matthias Cuntz

infonetcdf(*args, **kwargs)[source]#

Wrapper for ncinfo()

ncinfo(ncfile, var='', *, code=-1, variables=False, codes=False, long_names=False, units=False, dims=False, shape=False, attributes=False, sort=True)[source]#

Get information on variables in a netcdf file

Parameters:

  • ncfile (str) – netCDF file name

  • var (str, optional) – Variable name, only relevant if dims or attributes are True var takes precedence over code.

  • code (int, optional) – Variable code such as in files coming from GRIB, only relevant if dims or attributes are True. var takes precedence over code.

  • variables (bool, optional) – Get list of variables in ncfile

  • codes (bool, optional) – Get list of variable attributes code Missing codes will be filled with -1.

  • long_names (bool, optional) – Get list of variable attributes long_name Missing long_names will be filled with ‘’.

  • units (bool, optional) – Get list of variable attributes units. Missing units will be filled with ‘’.

  • dims (bool, optional) – Get tuple of dimension names for the variable with name var or number code.

  • shape (bool, optional) – Get shape of the variable with name var or number code.

  • attributes (bool, optional) – Get dictionary of all attributes of variable with name var or number code, or all file attributes of ncfile if var and code are not given

  • sort (bool, optional) – If True (default), sort output of variables, codes, units, and long_names with variable name as the sort key

Returns:

  • tuple of variable dimension names,

  • tuple of variable dimensions,

  • list of variable names, codes, units, long_names, or

  • dictionary of attributes

Examples

Get variable names

>>> ncfile = 'test_ncread.nc'
>>> print([ str(i) for i in ncinfo(ncfile, variables=True) ])
['x', 'y', 'is1', 'is2']
>>> print([ str(i)
...        for i in ncinfo(ncfile, variables=True, sort=True) ])
['is1', 'is2', 'x', 'y']

Get codes

>>> print(ncinfo(ncfile, codes=True))
[128, 129, -1, -1]
>>> print(ncinfo(ncfile, codes=True, sort=True))
[128, 129, -1, -1]
>>> print(ncinfo(ncfile, codes=True, sort=False))
[-1, -1, 128, 129]

Get special attributes units and long_names

>>> print([ str(i) for i in ncinfo(ncfile, units=True) ])
['arbitrary', 'arbitrary', 'xx', 'yy']
>>> print([ str(i) for i in ncinfo(ncfile, units=True, sort=False) ])
['xx', 'yy', 'arbitrary', 'arbitrary']
>>> print([ str(i) for i in ncinfo(ncfile, long_names=True) ])
['all ones', 'all twos', 'x-axis', 'y-axis']

Get dims

>>> print([ str(i) for i in ncinfo(ncfile, var='is1', dims=True) ])
['y', 'x']

Get shape

>>> print(ncinfo(ncfile, 'is1', shape=True))
(2, 4)

Get attributes

>>> t1 = ncinfo(ncfile, 'is1', attributes=True)
>>> print([ str(i) for i in sorted(t1) ])
['code', 'long_name', 'units']
Contents