"1" .')
/// >>> list(parse(input, "text/turtle", base_iri="http://example.com/"))
/// [ predicate= object=>>]
#[pyfunction]
#[text_signature = "(input, /, mime_type, *, base_iri = None)"]
pub fn parse(
input: &PyAny,
mime_type: &str,
base_iri: Option<&str>,
py: Python<'_>,
) -> PyResult {
let input = BufReader::new(PyFileLike::new(input.to_object(py)));
if let Some(graph_format) = GraphFormat::from_media_type(mime_type) {
let mut parser = GraphParser::from_format(graph_format);
if let Some(base_iri) = base_iri {
parser = parser
.with_base_iri(base_iri)
.map_err(|e| ValueError::py_err(e.to_string()))?;
}
Ok(PyTripleReader {
inner: parser.read_triples(input).map_err(map_io_err)?,
}
.into_py(py))
} else if let Some(dataset_format) = DatasetFormat::from_media_type(mime_type) {
let mut parser = DatasetParser::from_format(dataset_format);
if let Some(base_iri) = base_iri {
parser = parser
.with_base_iri(base_iri)
.map_err(|e| ValueError::py_err(e.to_string()))?;
}
Ok(PyQuadReader {
inner: parser.read_quads(input).map_err(map_io_err)?,
}
.into_py(py))
} else {
Err(ValueError::py_err(format!(
"Not supported MIME type: {}",
mime_type
)))
}
}
/// Serializes an RDF graph or dataset
///
/// It currently supports the following formats:
///
/// * `N-Triples `_ (``application/n-triples``)
/// * `N-Quads `_ (``application/n-quads``)
/// * `Turtle `_ (``text/turtle``)
/// * `TriG `_ (``application/trig``)
/// * `RDF/XML `_ (``application/rdf+xml``)
///
/// It supports also some MIME type aliases.
/// For example ``application/turtle`` could also be used for `Turtle `_
/// and ``application/xml`` for `RDF/XML `_.
///
/// :param input: the RDF triples and quads to serialize
/// :type input: iter(Triple) or iter(Quad)
/// :param output: The binary I/O object to write to. For example, it could be a file opened in binary mode with ``open('my_file.ttl', 'wb')``.
/// :type output: io.RawIOBase or io.BufferedIOBase
/// :param mime_type: the MIME type of the RDF serialization
/// :type mime_type: str
/// :raises ValueError: if the MIME type is not supported
/// :raises TypeError: if a triple is given during a quad format serialization or reverse
///
/// >>> output = io.BytesIO()
/// >>> serialize([Triple(NamedNode('http://example.com'), NamedNode('http://example.com/p'), Literal('1'))], output, "text/turtle")
/// >>> output.getvalue()
/// b' "1" .\n'
#[pyfunction]
#[text_signature = "(input, output, /, mime_type, *, base_iri = None)"]
pub fn serialize(input: &PyAny, output: &PyAny, mime_type: &str, py: Python<'_>) -> PyResult<()> {
let output = PyFileLike::new(output.to_object(py));
if let Some(graph_format) = GraphFormat::from_media_type(mime_type) {
let mut writer = GraphSerializer::from_format(graph_format)
.triple_writer(output)
.map_err(map_io_err)?;
for i in input.iter()? {
writer
.write(&*i?.downcast::>()?.borrow())
.map_err(map_io_err)?;
}
writer.finish().map_err(map_io_err)?;
Ok(())
} else if let Some(dataset_format) = DatasetFormat::from_media_type(mime_type) {
let mut writer = DatasetSerializer::from_format(dataset_format)
.quad_writer(output)
.map_err(map_io_err)?;
for i in input.iter()? {
writer
.write(&*i?.downcast::>()?.borrow())
.map_err(map_io_err)?;
}
writer.finish().map_err(map_io_err)?;
Ok(())
} else {
Err(ValueError::py_err(format!(
"Not supported MIME type: {}",
mime_type
)))
}
}
#[pyclass(unsendable, name= TripleReader)]
pub struct PyTripleReader {
inner: TripleReader>,
}
#[pyproto]
impl PyIterProtocol for PyTripleReader {
fn __iter__(slf: PyRefMut) -> Py {
slf.into()
}
fn __next__(mut slf: PyRefMut) -> PyResult> {
slf.inner
.next()
.map(|q| Ok(q.map_err(map_io_err)?.into()))
.transpose()
}
}
#[pyclass(unsendable, name= QuadReader)]
pub struct PyQuadReader {
inner: QuadReader>,
}
#[pyproto]
impl PyIterProtocol for PyQuadReader {
fn __iter__(slf: PyRefMut) -> Py {
slf.into()
}
fn __next__(mut slf: PyRefMut) -> PyResult> {
slf.inner
.next()
.map(|q| Ok(q.map_err(map_io_err)?.into()))
.transpose()
}
}
pub struct PyFileLike {
inner: PyObject,
}
impl PyFileLike {
pub fn new(inner: PyObject) -> Self {
Self { inner }
}
}
impl Read for PyFileLike {
fn read(&mut self, mut buf: &mut [u8]) -> io::Result {
let gil = Python::acquire_gil();
let py = gil.python();
let read = self
.inner
.call_method(py, "read", (buf.len(),), None)
.map_err(|e| to_io_err(e, py))?;
let bytes: &PyBytes = read.cast_as(py).map_err(|e| to_io_err(e, py))?;
buf.write_all(bytes.as_bytes())?;
Ok(bytes.len()?)
}
}
impl Write for PyFileLike {
fn write(&mut self, buf: &[u8]) -> io::Result {
let gil = Python::acquire_gil();
let py = gil.python();
Ok(usize::extract(
self.inner
.call_method(py, "write", (PyBytes::new(py, buf),), None)
.map_err(|e| to_io_err(e, py))?
.as_ref(py),
)
.map_err(|e| to_io_err(e, py))?)
}
fn flush(&mut self) -> io::Result<()> {
let gil = Python::acquire_gil();
let py = gil.python();
self.inner.call_method(py, "flush", (), None)?;
Ok(())
}
}
fn to_io_err(error: impl Into, py: Python<'_>) -> io::Error {
if let Ok(message) = error
.into()
.to_object(py)
.call_method(py, "__str__", (), None)
{
if let Ok(message) = message.extract::(py) {
io::Error::new(io::ErrorKind::Other, message)
} else {
io::Error::new(io::ErrorKind::Other, "An unknown error has occurred")
}
} else {
io::Error::new(io::ErrorKind::Other, "An unknown error has occurred")
}
}