addmeta

Add meta data to netCDF files.

Metadata

The metadata is stored in attribute files in YAML format. The metadata is in key-value pairs and is a global attribute if defined in a global section, or applied to a specific named variable in the variables section.

If an attribute is listed with a missing value that attribute is deleted from the file.

For example the following is an example of an attribute file:

global:
    # Mandatory since it gives a key to all the other attributes
    Conventions: "CF-1.7, ACDD-1.3"
    # The url of the license applied to the data
    license: "http://creativecommons.org/licenses/by-nc-sa/4.0/"
variables:
    yt_ocean:
        _FillValue:
        long_name: "latitude in rotated pole grid"
        units: "degrees"
    geolat_t:
        long_name: "latitude coordinate"
        units: "degrees_north"
        standard_name: "latitude"

It will create (or replace) two global attributes: Conventions and license. It will also create (or replace) attributes for two variables, yt_ocean and geolat_t, and delete the _FillValue attribute of yt_ocean.

The information is read into a python dict. Multiple attribute files can be specified. If the same attribute is defined more than once, the last attribute file specified takes precedence. Like cascading style sheets this means default values can be given and overridden when necessary.

Invocation

addmeta is a command line program. Invoking with the -h flag prints a summay of how to invoke the program correctly.

$ addmeta -h
usage: addmeta [-h] [-m METAFILES] [-l METALIST] [-v] files [files ...]

Add meta data to one or more netCDF files

positional arguments:
files                 netCDF files

optional arguments:
-h, --help            show this help message and exit
-m METAFILES, --metafiles METAFILES
                        One or more meta-data files in YAML format
-l METALIST, --metalist METALIST
                        File containing a list of meta-data files
-v, --verbose         Verbose output

Multiple attribute files can be specified by passing more than one file with the -m option. For a large number of files this can be tedious. In that case use the -l option and pass it a text file with the names of attribute files, one per line.

Multiple meta list files and meta files can be specified on one command line.