accessing area type and region vocabularies

[taylor13]

Question

From a code, say written in python, can one directly read the list of area types (found here) or the list of regions (found here)? I see they are displayed as html files, but is that built on a reference source, or is that the reference source.

We're writing a code that needs to check the input provided by a user against the CF controlled vocabularies.

I guess I'd be curious also how one would check whether a standard_name provided by a user is in the CF list of standard names.

[PythonCHB]

The html is not the source, though I’m not CC sure where the actual source is.

I’m sure someone else can answer your question directly, but there are at least a couple cf-checkers available:

https://github.com/cf-convention/cf-convention.github.io/blob/main/software.md

I’d take a look at their code to see where they are getting the vocabularies.

[taylor13]

Nice lead, @PythonCHB. In the checker the paths are given as:

STANDARDNAME = 'http://cfconventions.org/Data/cf-standard-names/current/src/cf-standard-name-table.xml'
AREATYPES = 'http://cfconventions.org/Data/area-type-table/current/src/area-type-table.xml'
REGIONNAMES = 'http://cfconventions.org/Data/standardized-region-list/standardized-region-list.xml'

And the xml's are fairly simply structured. For example, here's the beginning of the area types xml:

<area_type_table xsi:noNamespaceSchemaLocation="area-type-table-1.1.xsd">
    <title>Area Type Table</title>
    <version_number>11</version_number>
    <date>06 July 2023</date>
    <institution>Centre for Environmental Data Analysis</institution>
    <contact>[email protected]</contact>
    <entry id="air">
        <description>
            The area type of "air" distinguishes the atmospheric portion of a domain from the land portion (or any
            other non-air portion). It is needed when a variable such as wind speed is reported, for example, on a 
            surface at mean sea level  pressure. At most locations over land, this surface would be underground 
            and would need to be excluded from consideration, which could be indicated by specifying a 
            cell_ methods "where air".
        </description>
    </entry>
    <entry id="all_area_types">
        <description/>
    </entry>
<entry id="bare_ground">
<description/>

So I suppose, you just need to ingest the xml. Have I got that right? Do we all agree that those xml's are the reference controlled vocabularies?

[davidhassell]

those xml's are the reference controlled vocabularies?

That is indeed my assumption.

[japamment]

Hi @taylor13,

I can confirm that the xml files in the "current" directories are indeed the controlled vocabularies. The region names and area types are structured very similarly to the xml for the standard name table, except they have no units tag. The html versions of the table are rendered from these xml files for ease of browsing.

[taylor13]

I'm curious why "xml" is perferred to "json" as a format. I've always found the json files easier for humans to read and also trivial to ingest using python. I suppose there is some historical reason.