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RDFLib
======
[](https://travis-ci.org/RDFLib/rdflib)
[](https://coveralls.io/r/RDFLib/rdflib?branch=master)
[](https://github.com/RDFLib/rdflib/stargazers)
[](https://pypi.python.org/pypi/rdflib)
[](https://pypi.python.org/pypi/rdflib)
RDFLib is a pure Python package for working with [RDF](http://www.w3.org/RDF/). RDFLib contains most things you need to work with RDF, including:
* parsers and serializers for RDF/XML, N3, NTriples, N-Quads, Turtle, TriX, Trig and JSON-LD (via a plugin).
* a Graph interface which can be backed by any one of a number of Store implementations
* store implementations for in-memory storage and persistent storage on top of the Berkeley DB
* a SPARQL 1.1 implementation - supporting SPARQL 1.1 Queries and Update statements
## RDFlib Family of packages
The RDFlib community maintains many RDF-related Python code repositories with different purposes. For example:
* [rdflib](https://github.com/RDFLib/rdflib) - the rdflib core
* [sparqlwrapper](https://github.com/RDFLib/sparqlwrapper) - a simple Python wrapper around a SPARQL service to remotely execute your queries
* [pyLODE](https://github.com/RDFLib/pyLODE) - An OWL ontology documentation tool using Python and templating, based on LODE.
* [rdflib-jsonld](https://github.com/RDFLib/rdflib-jsonld) - an rdflib plugin that is an implementation of JSON-LD
Please see the list for all packages/repositories here:
* <https://github.com/RDFLib>
## Installation
RDFLib may be installed with Python's package management tool *pip*:
$ pip install rdflib
Alternatively manually download the package from the Python Package
Index (PyPI) at https://pypi.python.org/pypi/rdflib
The current version of RDFLib is 5.0.0, see the ``CHANGELOG.md``
file for what's new in this release.
## Getting Started
RDFLib aims to be a pythonic RDF API. rdflib's main data object is a `Graph` which is a Python collection
of RDF *Subject, Predicate, Object* Triples:
To create graph and load it with RDF data from DBPedia then print the results:
```python
import rdflib
g = rdflib.Graph()
g.load('http://dbpedia.org/resource/Semantic_Web')
for s, p, o in g:
print(s, p, o)
```
The components of the triples are URIs (resources) or Literals
(values).
URIs are grouped together by *namespace*, common namespaces are
included in RDFLib:
```python
from rdflib.namespace import DC, DCTERMS, DOAP, FOAF, SKOS, OWL, RDF, RDFS, VOID, XMLNS, XSD
```
You can use them like this:
```python
semweb = rdflib.URIRef('http://dbpedia.org/resource/Semantic_Web')
type = g.value(semweb, rdflib.RDFS.label)
```
Where `rdflib.RDFS` is the RDFS Namespace, `graph.value` returns an
object of the triple-pattern given (or an arbitrary one if more
exist).
Or like this, adding a triple to a graph `g`:
```python
g.add((
rdflib.URIRef("http://example.com/person/nick"),
FOAF.givenName,
rdflib.Literal("Nick", datatype=XSD.string)
))
```
The triple (in n-triples notation) `<http://example.com/person/nick> <http://xmlns.com/foaf/0.1/givenName> "Nick"^^<http://www.w3.org/2001/XMLSchema#string> .`
is created where the property `FOAF.giveName` is the URI `<http://xmlns.com/foaf/0.1/givenName>` and `XSD.string` is the
URI `<http://www.w3.org/2001/XMLSchema#string>`.
You can bind namespaces to prefixes to shorten the URIs for RDF/XML, Turtle, N3, TriG, TriX & JSON-LD serializations:
```python
g.bind("foaf", FOAF)
g.bind("xsd", XSD)
```
This will allow the n-triples triple above to be serialised like this:
```python
print(g.serialize(format="turtle").decode("utf-8"))
```
With these results:
```turtle
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
<http://example.com/person/nick> foaf:givenName "Nick"^^xsd:string .
```
New Namespaces can also be defined:
```python
dbpedia = rdflib.Namespace('http://dbpedia.org/ontology/')
abstracts = list(x for x in g.objects(semweb, dbpedia['abstract']) if x.language=='en')
```
See also [./examples](./examples)
## Features
The library contains parsers and serializers for RDF/XML, N3,
NTriples, N-Quads, Turtle, TriX, RDFa and Microdata. JSON-LD parsing/serializing can be achieved using the
[JSON-LD plugin](https://github.com/RDFLib/rdflib-jsonld).
The library presents a Graph interface which can be backed by
any one of a number of Store implementations.
This core RDFLib package includes store implementations for
in-memory storage and persistent storage on top of the Berkeley DB.
A SPARQL 1.1 implementation is included - supporting SPARQL 1.1 Queries and Update statements.
RDFLib is open source and is maintained on [GitHub](https://github.com/RDFLib/rdflib/). RDFLib releases, current and previous
are listed on [PyPI](https://pypi.python.org/pypi/rdflib/)
Multiple other projects are contained within the RDFlib "family", see <https://github.com/RDFLib/>.
## Documentation
See <https://rdflib.readthedocs.io> for our documentation built from the code.
## Support
For general "how do I..." queries, please use https://stackoverflow.com and tag your question with `rdflib`.
Existing questions:
* <https://stackoverflow.com/questions/tagged/rdflib>
## Releases
See <https://rdflib.dev> for the release schedule.
## Contributing
rdflib survives and grows via user contributions! Please consider lodging Pull Requests here:
* <https://github.com/RDFLib/rdflib/pulls>
You can also raise issues here:
* <https://github.com/RDFLib/rdflib/issues>
## Contacts
If you want to contact the rdflib maintainers, please do so via the rdflib-dev mailing list:
* <https://groups.google.com/group/rdflib-dev>
|
