orianac / nco-bindings

Language bindings for NCO

nco-bindings

Language bindings for NCO. A fork from Ralf Mueller's cdo-bindings.

nco.py - Use Python to access the power of NCO

This package contains the module NCO, which implements a python style access to the NetCDF Operators NCO. NCO is a command line tool for processing netCDF data. Its main focus if climate data, but it can by used for other purposes too.

Installation

Python Installation

./setup.py install

Coming Soon: Download and install nco.py via pypi:

pip install nco

Requirements

nco.py requires working NCO binaries, but has does not have special python version requirements. For returning multi-dimensional arrays (numpy addtional netcdf-io modules are needed. These are scipy or netCDF-4.

Usage

Run operators

For python an instance has to be created first

nco = Nco()

Now any NCO command (i.e. ncks, ncra, ...) can be called as a method of nco.

• Required argument

  • input - Input netcdf file name, str

• Optional arguments

  • output - String or list of strings representing input netCDF filenames. If not provided and operator returns a file (not an array or stdout text), the method will return a temporary file.
  • debug - bool or int, if <0 or True, debug statements will be turned on for NCO and NCOpy (default=False)
  • returnCdf - return a netCDF file handle, bool (default=False)
  • returnArray - return a numpy array of variable name, str (default='')
  • returnMaArray - return a numpy masked array of variable name, str (default='')
  • options - a string of NCO input options, for example options='-7 -L 1' (default='')
  • **kwargs - any kwarg will be passed as a key, value pair to the nco command "--{key}={value}". This allows the user to pass any number of long name commands list in the nco help pages.

• File information

  ncdump_string = nco.ncdump(input=ifile)

• Operators with user defined regular output files

  nco.ncra(input=ifile, output=ofile)

• Use temporary output files

  temp_ofile = nco.ncrcat(input=ifile)

• Set global NCO options

  nco.ncks(input=ifile, output=ofile, options="--netcdf4")

• Return multi-dimension arrrays

  temperatures = nco.ncra(input=ifile, returnArray=True).variables['T'][:] temperatures = nco.ncra(input=ifile, returnCdf=True).variables['T'][:] temperatures = nco.ncra(input=ifile, returnArray='T')

Tempfile helpers

nco.py includes a simple tempfile wrapper, which make live easier, when writing your own scripts

Support, Issues, Bugs, ...

Please use the github page for this code: https://github.com/jhamman/nco-bindings

Changelog

• next:
  • add ncdump --> python dictionary function

License

nco.py makes use of the GPLv2 License, see COPYING

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Other stuff

• Author: Joe Hamman [email protected]
• Requires: NCO version 4.x.x or newer
• License: Copyright 2013 by Joe Hamman. Released under GPLv2 license. See the COPYING file included in the distribution.