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README.md

WikidataQueryServiceR

Project Status: Active – The project has reached a stable, usable state and is being actively developed. CRAN_Status_Badge CRAN Total Downloads License: MIT

This is an R wrapper for the Wikidata Query Service (WDQS) which provides a way for tools to query Wikidata via SPARQL (see the beta at https://query.wikidata.org/). It is written in and for R, and was inspired by Oliver Keyes' WikipediR and WikidataR packages.

Author: Mikhail Popov (Wikimedia Foundation)
License: MIT
Status: Active

Installation

install.packages("WikidataQueryServiceR")

To install the development version:

# install.packages(c("devtools", "httr", "dplyr", "jsonlite"))
devtools::install_github("bearloga/WikidataQueryServiceR")

Usage

library(WikidataQueryServiceR)

You submit SPARQL queries using the query_wikidata() function.

Example: fetching genres of a particular movie

In this example, we find an "instance of" (P31) "film" (Q11424) that has the label "The Cabin in the Woods" (Q45394), get its genres (P136), and then use WDQS label service to return the genre labels.

query_wikidata('SELECT DISTINCT
  ?genre ?genreLabel
WHERE {
  ?film wdt:P31 wd:Q11424.
  ?film rdfs:label "The Cabin in the Woods"@en.
  ?film wdt:P136 ?genre.
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}')
## 5 rows were returned by WDQS
genre genreLabel
http://www.wikidata.org/entity/Q471839 science fiction film
http://www.wikidata.org/entity/Q1342372 monster film
http://www.wikidata.org/entity/Q224700 comedy horror
http://www.wikidata.org/entity/Q200092 horror film
http://www.wikidata.org/entity/Q859369 comedy-drama

For more example SPARQL queries, see this page on Wikidata.

query_wikidata() can accept multiple queries, returning a (potentially named) list of data frames. If the vector of SPARQL queries is named, the results will inherit those names.

Fetching queries from Wikidata's examples page

The package provides a WikipediR-based function for getting SPARQL queries from the WDQS examples page.

sparql_query <- get_example(c("Cats", "Horses", "Largest cities with female mayor"))
sparql_query[["Largest cities with female mayor"]]
 #added before 2016-10
#TEMPLATE={"template":"Largest ?c with ?sex head of government","variables":{"?sex":{"query":" SELECT ?id WHERE { ?id wdt:P31 wd:Q48264 .  } "},"?c":{"query":"SELECT DISTINCT ?id WHERE {  ?c wdt:P31 ?id.  ?c p:P6 ?mayor. }"} } }
SELECT DISTINCT ?city ?cityLabel ?mayor ?mayorLabel 
WHERE 
{
  BIND(wd:Q6581072 AS ?sex)
  BIND(wd:Q515 AS ?c)
    ?city wdt:P31/wdt:P279* ?c .  # find instances of subclasses of city
    ?city p:P6 ?statement .            # with a P6 (head of goverment) statement
    ?statement ps:P6 ?mayor .          # ... that has the value ?mayor
    ?mayor wdt:P21 ?sex .       # ... where the ?mayor has P21 (sex or gender) female
    FILTER NOT EXISTS { ?statement pq:P582 ?x }  # ... but the statement has no P582 (end date) qualifier
     
    # Now select the population value of the ?city
    # (wdt: properties use only statements of "preferred" rank if any, usually meaning "current population")
    ?city wdt:P1082 ?population .
    # Optionally, find English labels for city and mayor:
    SERVICE wikibase:label {
        bd:serviceParam wikibase:language "en" .
    }
}
ORDER BY DESC(?population)
LIMIT 10 

Now we can run all three extracted SPARQL queries and get back three data.frames:

results <- query_wikidata(sparql_query)
## 116 rows were returned by WDQS

## 6951 rows were returned by WDQS

## 10 rows were returned by WDQS
results$`Largest cities with female mayor`[, c("cityLabel", "mayorLabel")]
cityLabel mayorLabel
Tokyo Yuriko Koike
Mumbai Snehal Ambekar
Yokohama Fumiko Hayashi
Caracas Helen Fernández
Madrid Manuela Carmena
Surabaya Tri Rismaharini
Rome Virginia Raggi
Paris Anne Hidalgo
Houston Annise Parker
Antananarivo Lalao Ravalomanana

Links for learning SPARQL

Additional Information

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.