idloc

idloc is a command line utility and small function library for getting JSON-LD from the Library of Congress Linked Data service at https://id.loc.gov.

Ideally idloc would not be needed at all because you could just use curl or whatever HTTP library you want to fetch the JSON-LD directly. But at the moment the JSON-LD that is returned, while valid, isn't exactly usable and needs to be framed. idloc uses pyld internally to do the framing that makes the JSON usable by someone who just wants to use the data as JSON without the cognitive overhead of using RDF processing tools.

Install

This will install idloc and its dependencies:

pip install idloc

CLI

Once installed you should also have a idloc command line utility available. There are four commands get, lucky, search, concept-schemes.

Get

Get will fetch the id.loc.gov entity by URI and print out the framed JSON-LD:

$ idloc get https://id.loc.gov/authorities/subjects/sh2002000569

To see the output of this command see this file since it's really too long to include inline here in the docs.

Compare that to the JSON that is being made available at https://id.loc.gov/authorities/subjects/sh85021262.json and you will probably see why framing the JSON-LD is currently needed if you want to work with the data as JSON.

Lucky

If you want to roll the dice and see the JSON-LD for first entity that matches a given string:

$ idloc lucky "Semantic Web"

If you want to limit to particular concept schemes like subject-headings you can:

$idloc lucky --concept-scheme subject-headings "Semantic Web"

Search

You can search for entities:

$ idloc search "Semantic Web" --limit 5

International Semantic Web Conference (6th : 2007 : Pusan, Korea) Semantic Web : 6th International Semantic Web Conference, 2nd Asian Semantic Web Conference, ISWC 2007 + ASWC 2007, Busan, Korea, November 11-15, 2007 : proceedings
<http://id.loc.gov/resources/works/15024802>

International Semantic Web Conference (6th : 2007 : Pusan, Korea) The Semantic Web : 6th International Semantic Web Conference, 2nd Asian Semantic Web Conference, ISWC 2007 + ASWC 2007, Busan, Korea, November 11-15, 2007 : proceedings Berlin ; New York : Springer, 2007.
<http://id.loc.gov/resources/instances/15024802>

IFIP WG 12.5 Working Conference on Industrial Applications of Semantic Web (1st : 2005 : Jyväskylä, Finland) Industrial applications of semantic Web : proceedings of the 1st IFIP WG12.5 Working Conference on Industrial Applications of Semantic Web, August 25-27, 2005, Jyväskylä, Finland New York : Springer, c2005.
<http://id.loc.gov/resources/instances/14054943>

International Semantic Web Conference (1st : 2002 : Sardinia, Italy) semantic Web-ISWC 2002 : First International Semantic Web Conference, Sardinia, Italy, June 9-12, 2002 : proceedings
<http://id.loc.gov/resources/works/12761651>

International Semantic Web Conference (1st : 2002 : Sardinia, Italy) The semantic Web-ISWC 2002 : First International Semantic Web Conference, Sardinia, Italy, June 9-12, 2002 : proceedings Berlin ; New York : Springer, c2002.
<http://id.loc.gov/resources/instances/12761651>

Notice how the top 5 were taken up with bibframe instances? Similar to get you can limit a search to one or more concept schemes. For example if we want to search for "Semantic Web" only in the subject-headings and name-authority concept schemes:

$ idloc search --concept-scheme subject-headings --concept-scheme name-authority "Semantic Web" 

Concept Schemes

You may be wondering what concept schemes are available. To see a list of them:

$ idloc concept-schemes

Use as a Library

The idloc Python library can be used in your Python programs.

Get

You can get the JSON-LD for a given id.loc.gov URI:

import idloc

concept = idloc.get('http://id.loc.gov/authorities/subjects/sh2002000569')

Search

You can search for entities:

for result in idloc.search('Semantic Web'):
    print(result['title'], result['uri']

Similarly you can limit to particular concept schemes:

for result in idloc.search('Semantic Web', concept_schemes=['subject-headings', 'name-authority']):
    print(result['title'], result['uri'])

By default you get the first 20 results, but you can use the limit parameter to get more. If you set limit to 0 it will page through all the results.

Concept Schemes

A mapping of concept scheme names and their corresponding URIs is available in:

idloc.CONCEPT_SCHEMES

There are 130 of them! There is also a function idloc.concept_schemes() which will scrape the search interface at https://id.loc.gov/search to determine what the latest group of concept schemes is.