ouisparql 0.1.0

Simple SPARQL in Python

SPARQL is code. Write it, version control it, comment it, and run it using files. Writing your SPARQL code in Python programs as strings doesn’t allow you to easily reuse them in SPARQL GUIs or CLI tools. With ouisparql you can organize your SPARQL statements in .sparql files, load them into your python application as methods to call without losing the ability to use them as you would any other SPARQL file.

This module is an implementation of Kris Jenkins’ yesql Clojure library to the Python ecosystem, adapted from aiosql for SPARQL.

Badges

Usage

Install from pypi, for instance by running pip install ouisparql.

Install with pip from gitlab:

pip install  git+https://gitlab.com/sortion/ouisparql.git@main

Then write parametric SPARQL queries in a file and execute it from Python methods, e.g., this predicates.sparql file:

# name: get_predicates()
# Get the first two predicates in the database
SELECT DISTINCT ?predicate
WHERE {
      ?subject ?predicate ?object .
}

# name: get_subject_by_predicate(predicate)
# Get the first two subjects from a given predicate using a named parameter
SELECT DISTINCT ?subject
WHERE {
      ?subject :predicate ?object .
}

This example has an imaginary SPARQL endpoint with RDF triplets. It displays all predicates in the first example, and all subjects associated with a given predicate.

OuiSPARQL main feature is to be able to load queries from a SPARQL file and call them by name in python code. Query parameter declarations (e.g., (predicate)) are optional, and enforced when provided.

You can use ouisparql to load the queries in this file for use in your Python application:

import ouisparql
from SPARQLWrapper import SPARLQWrapper
sparql = SPARQLWrapper("https://query.wikidata.org/sparql", agent="OuiSPARQL documentation")
queries = ouisparql.from_path("queries.rq", "sparql_wrapper")
queries.get_all_predicate()
queries.get_subjects_by_predicate(predicate)

Why you might want to use this

• You think SPARQL is pretty good, and writing SPARQL is an important part of your applications.

• You don’t want to write your SPARQL in strings intermixed with your python code.

• You want to be able to reuse your SPARQL in other contexts, e.g., loading it into a SPARQL endpoint or other tools.

Why you might NOT want to use this

• You aren’t comfortable writing SPARQL code.

• Dynamically loaded objects built at runtime really bother you.