![](docs/_static/RDFlib.png)

# RDFLib

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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, JSON-LD and even HexTuples
* a Graph interface which can be backed by any one of a number of Store implementations
* Store implementations for in-memory, persistent on disk (Berkeley DB) and remote SPARQL endpoints
    * additional Stores can be supplied via plugins 
* a SPARQL 1.1 implementation - supporting SPARQL 1.1 Queries and Update statements
* SPARQL function extension mechanisms

## 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.
* [pyrdfa3](https://github.com/RDFLib/pyrdfa3) - RDFa 1.1 distiller/parser library: can extract RDFa 1.1/1.0 from (X)HTML, SVG, or XML in general.
* [pymicrodata](https://github.com/RDFLib/pymicrodata) - A module to extract RDF from an HTML5 page annotated with microdata.
* [pySHACL](https://github.com/RDFLib/pySHACL) - A pure Python module which allows for the validation of RDF graphs against SHACL graphs.
* [OWL-RL](https://github.com/RDFLib/OWL-RL) - A simple implementation of the OWL2 RL Profile which expands the graph with all possible triples that OWL RL defines.

Please see the list for all packages/repositories here:

* <https://github.com/RDFLib>

Help with maintenance of all of the RDFLib family of packages is always welcome and appreciated.

## Versions & Releases

* `main` branch in this repository is the current unstable release - version 8 alpha
* `7.4.0` a few small fixes, add test matrix for active python versions, and move v7 documentation to MkDocs
* `7.3.0` many fixes and usability improvements, particularly for the Dataset class. See changelog for details
* `7.2.1` tiny clean up release, relaxes Python version requirement
* `7.2.0` general fixes and usability improvements, see changelog for details
* `7.1.4` tidy-up release, possibly last 7.x release
* `7.1.3` current stable release, small improvements to 7.1.1
* `7.1.2` previously deleted release
* `7.1.1` previous stable release
    * see <https://github.com/RDFLib/rdflib/releases/tag/7.1.1>
* `7.0.0` previous stable release, supports Python 3.8.1+ only.
    * see [Releases](https://github.com/RDFLib/rdflib/releases)
* `6.x.y` supports Python 3.7+ only. Many improvements over 5.0.0
    * see [Releases](https://github.com/RDFLib/rdflib/releases)
* `5.x.y` supports Python 2.7 and 3.4+ and is [mostly backwards compatible with 4.2.2](https://rdflib.readthedocs.io/en/stable/upgrade4to5.html).

See <https://github.com/RDFLib/rdflib/releases/> for the release details.

## Documentation
See <https://rdflib.readthedocs.io> for our documentation built from the code. Note that there are `latest`, `stable` and versioned builds, such as `5.0.0`, matching releases.

## Installation
The stable release of RDFLib may be installed with Python's package management tool *pip*:

    $ pip install rdflib

Some features of RDFLib require optional dependencies which may be installed using *pip* extras:

    $ pip install rdflib[berkeleydb,networkx,html,lxml,orjson]

Alternatively manually download the package from the Python Package
Index (PyPI) at https://pypi.python.org/pypi/rdflib

### Installation of the current main branch (for developers)

With *pip* you can also install rdflib from the git repository with one of the following options:

    $ pip install git+https://github.com/rdflib/rdflib@main

or

    $ pip install -e git+https://github.com/rdflib/rdflib@main#egg=rdflib

or from your locally cloned repository you can install it with one of the following options:

    $ poetry install  # installs into a poetry-managed venv

or

    $ pip install -e .

## 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
from rdflib import Graph
g = Graph()
g.parse('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
from rdflib import Graph, URIRef, Literal
from rdflib.namespace import RDFS, XSD

g = Graph()
semweb = URIRef('http://dbpedia.org/resource/Semantic_Web')
type = g.value(semweb, RDFS.label)
```
Where `RDFS` is the RDFS namespace, `XSD` the XML Schema Datatypes namespace and `g.value` returns an object of the triple-pattern given (or an arbitrary one if multiple exist).

Or like this, adding a triple to a graph `g`:

```python
g.add((
    URIRef("http://example.com/person/nick"),
    FOAF.givenName,
    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.givenName` 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"))
```

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 = 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, JSON-LD, RDFa and Microdata.

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/>.

## Running tests

### Running the tests on the host

Run the test suite with `pytest`.
```shell
poetry install
poetry run pytest
```

### Running test coverage on the host with coverage report

Run the test suite and generate a HTML coverage report with `pytest` and `pytest-cov`.
```shell
poetry run pytest --cov
```

### Viewing test coverage

Once tests have produced HTML output of the coverage report, view it by running:
```shell
poetry run pytest --cov --cov-report term --cov-report html
python -m http.server --directory=htmlcov
```

## Contributing

RDFLib survives and grows via user contributions!
Please read our [contributing guide](https://rdflib.readthedocs.io/en/latest/CONTRIBUTING.html) and [developers guide](https://rdflib.readthedocs.io/en/latest/developers.html) to get started.
Please consider lodging Pull Requests here:

* <https://github.com/RDFLib/rdflib/pulls>

To get a development environment consider using Gitpod or Google Cloud Shell.

[Open in Gitpod](https://gitpod.io/#https://github.com/RDFLib/rdflib)
[Open in Cloud Shell](https://shell.cloud.google.com/cloudshell/editor?cloudshell_git_repo=https%3A%2F%2Fgithub.com%2FRDFLib%2Frdflib&cloudshell_git_branch=main&cloudshell_open_in_editor=README.md)

You can also raise issues here:

* <https://github.com/RDFLib/rdflib/issues>

## Support & Contacts
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>

If you want to contact the rdflib maintainers, please do so via:

* the rdflib-dev mailing list: <https://groups.google.com/group/rdflib-dev>
* the chat, which is available at [gitter](https://gitter.im/RDFLib/rdflib) or via matrix [#RDFLib_rdflib:gitter.im](https://matrix.to/#/#RDFLib_rdflib:gitter.im)
