term

This module defines the different types of terms. Terms are the kinds of objects that can appear in a quoted/asserted triple. This includes those that are core to RDF:

• Blank Nodes - Blank Nodes
• URI References - URI References
• Literals - Literals (which consist of a literal value, datatype and language tag)

Those that extend the RDF model into N3:

• QuotedGraph - Formulae
• Variable - Universal Quantifications (Variables)

And those that are primarily for matching against ‘Nodes’ in the underlying Graph:

• REGEX Expressions
• Date Ranges
• Numerical Ranges

Classes:

• BNode –

  RDF 1.1’s Blank Nodes Section: https://www.w3.org/TR/rdf11-concepts/#section-blank-nodes

• IdentifiedNode –

  An abstract class, primarily defined to identify Nodes that are not Literals.

• Identifier –

  See http://www.w3.org/2002/07/rdf-identifer-terminology/

• Literal –

  RDF 1.1’s Literals Section: http://www.w3.org/TR/rdf-concepts/#section-Graph-Literal

• Node –

  A Node in the Graph.

• URIRef –

  RDF 1.1’s IRI Section

• Variable –

  A Variable - this is used for querying, or in Formula aware

Functions:

• bind –

  register a new datatype<->pythontype binding

XSDToPython module-attribute

XSDToPython: Dict[Optional[str], Optional[Callable[[str], Any]]] = {None: None, URIRef(_XSD_PFX + 'time'): parse_time, URIRef(_XSD_PFX + 'date'): parse_xsd_date, URIRef(_XSD_PFX + 'dateTime'): parse_datetime, URIRef(_XSD_PFX + 'duration'): parse_xsd_duration, URIRef(_XSD_PFX + 'dayTimeDuration'): parse_xsd_duration, URIRef(_XSD_PFX + 'yearMonthDuration'): parse_xsd_duration, URIRef(_XSD_PFX + 'hexBinary'): _unhexlify, URIRef(_XSD_PFX + 'string'): None, URIRef(_XSD_PFX + 'normalizedString'): None, URIRef(_XSD_PFX + 'token'): None, URIRef(_XSD_PFX + 'language'): None, URIRef(_XSD_PFX + 'boolean'): _parseBoolean, URIRef(_XSD_PFX + 'decimal'): Decimal, URIRef(_XSD_PFX + 'integer'): long_type, URIRef(_XSD_PFX + 'nonPositiveInteger'): long_type, URIRef(_XSD_PFX + 'long'): long_type, URIRef(_XSD_PFX + 'nonNegativeInteger'): long_type, URIRef(_XSD_PFX + 'negativeInteger'): long_type, URIRef(_XSD_PFX + 'int'): int, URIRef(_XSD_PFX + 'unsignedLong'): long_type, URIRef(_XSD_PFX + 'positiveInteger'): long_type, URIRef(_XSD_PFX + 'short'): int, URIRef(_XSD_PFX + 'unsignedInt'): int, URIRef(_XSD_PFX + 'byte'): int, URIRef(_XSD_PFX + 'unsignedShort'): int, URIRef(_XSD_PFX + 'unsignedByte'): int, URIRef(_XSD_PFX + 'float'): float, URIRef(_XSD_PFX + 'double'): float, URIRef(_XSD_PFX + 'base64Binary'): b64decode, URIRef(_XSD_PFX + 'anyURI'): None, _RDF_XMLLITERAL: _parseXML}

__all__ module-attribute

__all__ = ['bind', '_is_valid_uri', 'Node', 'IdentifiedNode', 'Identifier', 'URIRef', 'BNode', 'Literal', 'Variable']

logger module-attribute

logger = getLogger(__name__)

rdflib_skolem_genid module-attribute

rdflib_skolem_genid = '/.well-known/genid/rdflib/'

skolem_genid module-attribute

skolem_genid = '/.well-known/genid/'

skolems module-attribute

skolems: Dict[str, BNode] = {}

BNode

Bases: IdentifiedNode

RDF 1.1’s Blank Nodes Section: https://www.w3.org/TR/rdf11-concepts/#section-blank-nodes

Blank Nodes are local identifiers for unnamed nodes in RDF graphs that are used in some concrete RDF syntaxes or RDF store implementations. They are always locally scoped to the file or RDF store, and are not persistent or portable identifiers for blank nodes. The identifiers for Blank Nodes are not part of the RDF abstract syntax, but are entirely dependent on particular concrete syntax or implementation (such as Turtle, JSON-LD).

---

RDFLib’s BNode class makes unique IDs for all the Blank Nodes in a Graph but you should never expect, or reply on, BNodes’ IDs to match across graphs, or even for multiple copies of the same graph, if they are regenerated from some non-RDFLib source, such as loading from RDF data.

Methods:

• __new__ –

  only store implementations should pass in a value

• __reduce__ –
• __repr__ –
• n3 –
• skolemize –

  Create a URIRef “skolem” representation of the BNode, in accordance

Attributes:

• __slots__ –

__slots__ class-attribute instance-attribute

__slots__ = ()

__new__

__new__(value: Optional[str] = None, _sn_gen: Optional[Union[Callable[[], str], Generator]] = None, _prefix: str = _unique_id())

only store implementations should pass in a value

Source code in rdflib/term.py

def __new__(
    cls,
    value: Optional[str] = None,
    _sn_gen: Optional[Union[Callable[[], str], Generator]] = None,
    _prefix: str = _unique_id(),
):
    """
    # only store implementations should pass in a value
    """
    if value is None:
        # so that BNode values do not collide with ones created with
        # a different instance of this module at some other time.
        if _sn_gen is not None:
            if callable(_sn_gen):
                sn_result: Union[str, Generator] = _sn_gen()
            else:
                sn_result = _sn_gen
            if isinstance(sn_result, GeneratorType):
                node_id = next(sn_result)
            else:
                node_id = sn_result
        else:
            node_id = uuid4().hex
        # note, for two (and only two) string variables,
        # concat with + is faster than f"{x}{y}"
        value = _prefix + f"{node_id}"
    else:
        # TODO: check that value falls within acceptable bnode value range
        # for RDF/XML needs to be something that can be serialized
        # as a nodeID for N3 ??  Unless we require these
        # constraints be enforced elsewhere?
        pass  # assert is_ncname(str(value)), "BNode identifiers
        # must be valid NCNames" _:[A-Za-z][A-Za-z0-9]*
        # http://www.w3.org/TR/2004/REC-rdf-testcases-20040210/#nodeID
    # type error: Incompatible return value type (got "Identifier", expected "BNode")
    return Identifier.__new__(cls, value)

__reduce__

__reduce__() -> Tuple[Type[BNode], Tuple[str]]

Source code in rdflib/term.py

def __reduce__(self) -> Tuple[Type[BNode], Tuple[str]]:
    return (BNode, (str(self),))

__repr__

__repr__() -> str

Source code in rdflib/term.py

def __repr__(self) -> str:
    if self.__class__ is BNode:
        clsName = "rdflib.term.BNode"  # noqa: N806
    else:
        clsName = self.__class__.__name__  # noqa: N806
    return f"{clsName}({str.__repr__(self)})"

n3

n3(namespace_manager: Optional[NamespaceManager] = None) -> str

Source code in rdflib/term.py

def n3(self, namespace_manager: Optional[NamespaceManager] = None) -> str:
    # note - for two strings, concat with + is faster than f"{x}{y}"
    return "_:" + self

skolemize

skolemize(authority: Optional[str] = None, basepath: Optional[str] = None) -> URIRef

Create a URIRef “skolem” representation of the BNode, in accordance with http://www.w3.org/TR/rdf11-concepts/#section-skolemization

Added in version 4.0

Source code in rdflib/term.py

def skolemize(
    self, authority: Optional[str] = None, basepath: Optional[str] = None
) -> URIRef:
    """Create a URIRef "skolem" representation of the BNode, in accordance
    with http://www.w3.org/TR/rdf11-concepts/#section-skolemization

    Added in version 4.0
    """
    if authority is None:
        authority = _SKOLEM_DEFAULT_AUTHORITY
    if basepath is None:
        basepath = rdflib_skolem_genid
    skolem = basepath + str(self)
    return URIRef(urljoin(authority, skolem))

Genid

Bases: URIRef

Attributes:

• __slots__ –

__slots__ class-attribute instance-attribute

__slots__ = ()

IdentifiedNode

Bases: Identifier

An abstract class, primarily defined to identify Nodes that are not Literals.

The name “Identified Node” is not explicitly defined in the RDF specification, but can be drawn from this section: https://www.w3.org/TR/rdf-concepts/#section-URI-Vocabulary

Methods:

• __getnewargs__ –
• n3 –
• toPython –

Attributes:

• __slots__ –

__slots__ class-attribute instance-attribute

__slots__ = ()

__getnewargs__

__getnewargs__() -> Tuple[str]

Source code in rdflib/term.py

def __getnewargs__(self) -> Tuple[str]:
    return (str(self),)

n3

n3(namespace_manager: Optional[NamespaceManager] = None) -> str

Source code in rdflib/term.py

def n3(self, namespace_manager: Optional[NamespaceManager] = None) -> str:
    raise NotImplementedError()

toPython

toPython() -> str

Source code in rdflib/term.py

def toPython(self) -> str:  # noqa: N802
    return str(self)

Identifier

Bases: Node, str

See http://www.w3.org/2002/07/rdf-identifer-terminology/ regarding choice of terminology.

Methods:

• __eq__ –

  Equality for Nodes.

• __ge__ –
• __gt__ –

  This implements ordering for Nodes.

• __le__ –
• __lt__ –
• __ne__ –
• __new__ –
• eq –

  A “semantic”/interpreted equality function,

• neq –

  A “semantic”/interpreted not equal function,

• startswith –

Attributes:

• __hash__ –
• __slots__ –

__hash__ class-attribute instance-attribute

__hash__ = __hash__

__slots__ class-attribute instance-attribute

__slots__ = ()

__eq__

__eq__(other: Any) -> bool

Equality for Nodes.

>>> BNode("foo")==None
False
>>> BNode("foo")==URIRef("foo")
False
>>> URIRef("foo")==BNode("foo")
False
>>> BNode("foo")!=URIRef("foo")
True
>>> URIRef("foo")!=BNode("foo")
True
>>> Variable('a')!=URIRef('a')
True
>>> Variable('a')!=Variable('a')
False

Source code in rdflib/term.py

def __eq__(self, other: Any) -> bool:
    """Equality for Nodes.

    ```python
    >>> BNode("foo")==None
    False
    >>> BNode("foo")==URIRef("foo")
    False
    >>> URIRef("foo")==BNode("foo")
    False
    >>> BNode("foo")!=URIRef("foo")
    True
    >>> URIRef("foo")!=BNode("foo")
    True
    >>> Variable('a')!=URIRef('a')
    True
    >>> Variable('a')!=Variable('a')
    False

    ```
    """

    if type(self) is type(other):
        return str(self) == str(other)
    else:
        return False

__ge__

__ge__(other: Any) -> bool

Source code in rdflib/term.py

def __ge__(self, other: Any) -> bool:
    r = self.__gt__(other)
    if r:
        return True
    return self == other

__gt__

__gt__(other: Any) -> bool

This implements ordering for Nodes.

This tries to implement this: http://www.w3.org/TR/sparql11-query/#modOrderBy

Variables are not included in the SPARQL list, but they are greater than BNodes and smaller than everything else

Source code in rdflib/term.py

def __gt__(self, other: Any) -> bool:
    """This implements ordering for Nodes.

    This tries to implement this:
    http://www.w3.org/TR/sparql11-query/#modOrderBy

    Variables are not included in the SPARQL list, but
    they are greater than BNodes and smaller than everything else
    """
    if other is None:
        return True  # everything bigger than None
    elif type(self) is type(other):
        return str(self) > str(other)
    elif isinstance(other, Node):
        return _ORDERING[type(self)] > _ORDERING[type(other)]

    return NotImplemented

__le__

__le__(other: Any) -> bool

Source code in rdflib/term.py

def __le__(self, other: Any) -> bool:
    r = self.__lt__(other)
    if r:
        return True
    return self == other

__lt__

__lt__(other: Any) -> bool

Source code in rdflib/term.py

def __lt__(self, other: Any) -> bool:
    if other is None:
        return False  # Nothing is less than None
    elif type(self) is type(other):
        return str(self) < str(other)
    elif isinstance(other, Node):
        return _ORDERING[type(self)] < _ORDERING[type(other)]

    return NotImplemented

__ne__

__ne__(other: Any) -> bool

Source code in rdflib/term.py

def __ne__(self, other: Any) -> bool:
    return not self.__eq__(other)

__new__

__new__(value: str)

Source code in rdflib/term.py

def __new__(cls, value: str):
    return str.__new__(cls, value)

eq

eq(other: Any) -> bool

A “semantic”/interpreted equality function, by default, same as eq

Source code in rdflib/term.py

def eq(self, other: Any) -> bool:
    """A "semantic"/interpreted equality function,
    by default, same as __eq__"""
    return self.__eq__(other)

neq

neq(other: Any) -> bool

A “semantic”/interpreted not equal function, by default, same as ne

Source code in rdflib/term.py

def neq(self, other: Any) -> bool:
    """A "semantic"/interpreted not equal function,
    by default, same as __ne__"""
    return self.__ne__(other)

startswith

startswith(prefix: str, start=..., end=...) -> bool

Source code in rdflib/term.py

def startswith(self, prefix: str, start=..., end=...) -> bool:  # type: ignore[override] # FIXME
    return str(self).startswith(str(prefix))

Literal

Bases: Identifier

RDF 1.1’s Literals Section: http://www.w3.org/TR/rdf-concepts/#section-Graph-Literal

Literals are used for values such as strings, numbers, and dates.

A literal in an RDF graph consists of two or three elements:

• a lexical form, being a Unicode string, which SHOULD be in Normal Form C
• a datatype IRI, being an IRI identifying a datatype that determines how the lexical form maps to a literal value, and
• if and only if the datatype IRI is http://www.w3.org/1999/02/22-rdf-syntax-ns#langString, a non-empty language tag. The language tag MUST be well-formed according to section 2.2.9 of Tags for identifying languages <http://tools.ietf.org/html/bcp47>_.

A literal is a language-tagged string if the third element is present. Lexical representations of language tags MAY be converted to lower case. The value space of language tags is always in lower case.

---

For valid XSD datatypes, the lexical form is optionally normalized at construction time. Default behaviour is set by rdflib.NORMALIZE_LITERALS and can be overridden by the normalize parameter to __new__

Equality and hashing of Literals are done based on the lexical form, i.e.:

>>> from rdflib.namespace import XSD
>>> Literal('01') != Literal('1')  # clear - strings differ
True

but with data-type they get normalized:

>>> Literal('01', datatype=XSD.integer) != Literal('1', datatype=XSD.integer)
False

unless disabled:

>>> Literal('01', datatype=XSD.integer, normalize=False) != Literal('1', datatype=XSD.integer)
True

Value based comparison is possible:

>>> Literal('01', datatype=XSD.integer).eq(Literal('1', datatype=XSD.float))
True

The eq method also provides limited support for basic python types:

>>> Literal(1).eq(1) # fine - int compatible with xsd:integer
True
>>> Literal('a').eq('b') # fine - str compatible with plain-lit
False
>>> Literal('a', datatype=XSD.string).eq('a') # fine - str compatible with xsd:string
True
>>> Literal('a').eq(1) # not fine, int incompatible with plain-lit
NotImplemented

Greater-than/less-than ordering comparisons are also done in value space, when compatible datatypes are used. Incompatible datatypes are ordered by DT, or by lang-tag. For other nodes the ordering is None < BNode < URIRef < Literal

Any comparison with non-rdflib Node are “NotImplemented” In PY3 this is an error.

>>> from rdflib import Literal, XSD
>>> lit2006 = Literal('2006-01-01',datatype=XSD.date)
>>> lit2006.toPython()
datetime.date(2006, 1, 1)
>>> lit2006 < Literal('2007-01-01',datatype=XSD.date)
True
>>> Literal(datetime.utcnow()).datatype
rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#dateTime')
>>> Literal(1) > Literal(2) # by value
False
>>> Literal(1) > Literal(2.0) # by value
False
>>> Literal('1') > Literal(1) # by DT
True
>>> Literal('1') < Literal('1') # by lexical form
False
>>> Literal('a', lang='en') > Literal('a', lang='fr') # by lang-tag
False
>>> Literal(1) > URIRef('foo') # by node-type
True

The > < operators will eat this NotImplemented and throw a TypeError (py3k):

>>> Literal(1).__gt__(2.0)
NotImplemented

Methods:

• __abs__ –

  Implements absolute value operation for Literals with numeric values.

• __add__ –

  ```python

• __bool__ –

  Determines the truth value of the Literal.

• __eq__ –

  Equality operator for Literals.

• __ge__ –
• __getstate__ –
• __gt__ –

  Implements the greater-than comparison for Literals.

• __hash__ –

  Hash function for Literals to enable their use as dictionary keys.

• __invert__ –

  Implements bitwise NOT operation for Literals with numeric values.

• __le__ –

  Less than or equal operator for Literals.

• __lt__ –
• __neg__ –

  Implements unary negation for Literals with numeric values.

• __new__ –

  Create a new Literal instance.

• __pos__ –

  Implements unary plus operation for Literals with numeric values.

• __reduce__ –
• __repr__ –
• __setstate__ –
• __sub__ –

  Implements subtraction between Literals or between a Literal and a Python object.

• eq –

  Compare the value of this literal with something else.

• n3 –

  Returns a representation in the N3 format.

• neq –
• normalize –

  Returns a new literal with a normalised lexical representation

• toPython –

  Returns an appropriate python datatype derived from this RDF Literal

Attributes:

• __slots__ –
• datatype (Optional[URIRef]) –
• ill_typed (Optional[bool]) –

  For `recognized datatype IRIs

• language (Optional[str]) –
• value (Any) –

__slots__ class-attribute instance-attribute

__slots__ = ('_language', '_datatype', '_value', '_ill_typed')

datatype property

datatype: Optional[URIRef]

ill_typed property

ill_typed: Optional[bool]

For recognized datatype IRIs <https://www.w3.org/TR/rdf11-concepts/#dfn-recognized-datatype-iris>, this value will be True if the literal is ill formed, otherwise it will be False. Literal.value (i.e. the literal value <https://www.w3.org/TR/rdf11-concepts/#dfn-literal-value>) should always be defined if this property is False, but should not be considered reliable if this property is True.

If the literal’s datatype is None or not in the set of recognized datatype IRIs <https://www.w3.org/TR/rdf11-concepts/#dfn-recognized-datatype-iris>_ this value will be None.

language property

language: Optional[str]

value property

value: Any

__abs__

__abs__() -> Literal

Implements absolute value operation for Literals with numeric values.

Example

# Absolute value of a negative integer Literal
abs(Literal(-1))
# rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# Using a string with a datatype
from rdflib.namespace import XSD
abs(Literal("-1", datatype=XSD.integer))
# rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# This will raise a TypeError
abs(Literal("1"))
# TypeError: Not a number; rdflib.term.Literal('1')

Source code in rdflib/term.py

def __abs__(self) -> Literal:
    """Implements absolute value operation for Literals with numeric values.

    Example:
        ```python
        # Absolute value of a negative integer Literal
        abs(Literal(-1))
        # rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # Using a string with a datatype
        from rdflib.namespace import XSD
        abs(Literal("-1", datatype=XSD.integer))
        # rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # This will raise a TypeError
        abs(Literal("1"))
        # TypeError: Not a number; rdflib.term.Literal('1')
        ```
    """
    if isinstance(self.value, (int, long_type, float)):
        return Literal(self.value.__abs__())
    else:
        raise TypeError(f"Not a number; {self!r}")

__add__

__add__(val: Any) -> Literal

>>> from rdflib.namespace import XSD
>>> Literal(1) + 1
rdflib.term.Literal('2', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))
>>> Literal("1") + "1"
rdflib.term.Literal('11')

# Handling dateTime/date/time based operations in Literals
>>> a = Literal('2006-01-01T20:50:00', datatype=XSD.dateTime)
>>> b = Literal('P31D', datatype=XSD.duration)
>>> (a + b)
rdflib.term.Literal('2006-02-01T20:50:00', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#dateTime'))
>>> from rdflib.namespace import XSD
>>> a = Literal('2006-07-01T20:52:00', datatype=XSD.dateTime)
>>> b = Literal('P122DT15H58M', datatype=XSD.duration)
>>> (a + b)
rdflib.term.Literal('2006-11-01T12:50:00', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#dateTime'))

Source code in rdflib/term.py

def __add__(self, val: Any) -> Literal:
    """
    ```python
    >>> from rdflib.namespace import XSD
    >>> Literal(1) + 1
    rdflib.term.Literal('2', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))
    >>> Literal("1") + "1"
    rdflib.term.Literal('11')

    # Handling dateTime/date/time based operations in Literals
    >>> a = Literal('2006-01-01T20:50:00', datatype=XSD.dateTime)
    >>> b = Literal('P31D', datatype=XSD.duration)
    >>> (a + b)
    rdflib.term.Literal('2006-02-01T20:50:00', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#dateTime'))
    >>> from rdflib.namespace import XSD
    >>> a = Literal('2006-07-01T20:52:00', datatype=XSD.dateTime)
    >>> b = Literal('P122DT15H58M', datatype=XSD.duration)
    >>> (a + b)
    rdflib.term.Literal('2006-11-01T12:50:00', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#dateTime'))

    ```
    """

    # if no val is supplied, return this Literal
    if val is None:
        return self

    # convert the val to a Literal, if it isn't already one
    if not isinstance(val, Literal):
        val = Literal(val)

    # if self is datetime based and value is duration
    if (
        self.datatype in (_XSD_DATETIME, _XSD_DATE)
        and val.datatype in _TIME_DELTA_TYPES
    ):
        date1: Union[datetime, date] = self.toPython()
        duration: Union[Duration, timedelta] = val.toPython()
        difference = date1 + duration
        return Literal(difference, datatype=self.datatype)

    # if self is time based and value is duration
    elif self.datatype == _XSD_TIME and val.datatype in _TIME_DELTA_TYPES:
        selfv: time = self.toPython()
        valv: Union[Duration, timedelta] = val.toPython()
        sdt = datetime.combine(date(2000, 1, 1), selfv) + valv
        return Literal(sdt.time(), datatype=self.datatype)

    # if self is datetime based and value is not or vice versa
    elif (
        (
            self.datatype in _ALL_DATE_AND_TIME_TYPES
            and val.datatype not in _ALL_DATE_AND_TIME_TYPES
        )
        or (
            self.datatype not in _ALL_DATE_AND_TIME_TYPES
            and val.datatype in _ALL_DATE_AND_TIME_TYPES
        )
        or (
            self.datatype in _TIME_DELTA_TYPES
            and (
                (val.datatype not in _TIME_DELTA_TYPES)
                or (self.datatype != val.datatype)
            )
        )
    ):
        raise TypeError(
            f"Cannot add a Literal of datatype {str(val.datatype)} to a Literal of datatype {str(self.datatype)}"
        )

    # if the datatypes are the same, just add the Python values and convert back
    if self.datatype == val.datatype:
        return Literal(
            self.toPython() + val.toPython(), self.language, datatype=self.datatype
        )
    # if the datatypes are not the same but are both numeric, add the Python values and strip off decimal junk
    # (i.e. tiny numbers (more than 17 decimal places) and trailing zeros) and return as a decimal
    elif (
        self.datatype in _NUMERIC_LITERAL_TYPES
        and val.datatype in _NUMERIC_LITERAL_TYPES
    ):
        return Literal(
            Decimal(
                f"{round(Decimal(self.toPython()) + Decimal(val.toPython()), 15):f}".rstrip(
                    "0"
                ).rstrip(
                    "."
                )
            ),
            datatype=_XSD_DECIMAL,
        )
    # in all other cases, perform string concatenation
    else:
        try:
            s = str.__add__(self, val)
        except TypeError:
            s = str(self.value) + str(val)

        # if the original datatype is string-like, use that
        if self.datatype in _STRING_LITERAL_TYPES:
            new_datatype = self.datatype
        # if not, use string
        else:
            new_datatype = _XSD_STRING

        return Literal(s, self.language, datatype=new_datatype)

__bool__

__bool__() -> bool

Determines the truth value of the Literal.

Used for if statements, bool(literal), etc.

Source code in rdflib/term.py

def __bool__(self) -> bool:
    """Determines the truth value of the Literal.

    Used for if statements, bool(literal), etc.
    """
    if self.value is not None:
        return bool(self.value)
    return len(self) != 0

__eq__

__eq__(other: Any) -> bool

Equality operator for Literals.

Literals are only equal to other literals.

Notes

“Two literals are equal if and only if all of the following hold: * The strings of the two lexical forms compare equal, character by character. * Either both or neither have language tags. * The language tags, if any, compare equal. * Either both or neither have datatype URIs. * The two datatype URIs, if any, compare equal, character by character.” – 6.5.1 Literal Equality (RDF: Concepts and Abstract Syntax)

Example

Literal("1", datatype=URIRef("foo")) == Literal("1", datatype=URIRef("foo"))
# True
Literal("1", datatype=URIRef("foo")) == Literal("1", datatype=URIRef("foo2"))
# False

Literal("1", datatype=URIRef("foo")) == Literal("2", datatype=URIRef("foo"))
# False
Literal("1", datatype=URIRef("foo")) == "asdf"
# False

from rdflib import XSD
Literal('2007-01-01', datatype=XSD.date) == Literal('2007-01-01', datatype=XSD.date)
# True
Literal('2007-01-01', datatype=XSD.date) == date(2007, 1, 1)
# False

Literal("one", lang="en") == Literal("one", lang="en")
# True
Literal("hast", lang='en') == Literal("hast", lang='de')
# False

Literal("1", datatype=XSD.integer) == Literal(1)
# True
Literal("1", datatype=XSD.integer) == Literal("01", datatype=XSD.integer)
# True

Source code in rdflib/term.py

def __eq__(self, other: Any) -> bool:
    """Equality operator for Literals.

    Literals are only equal to other literals.

    Notes:
        "Two literals are equal if and only if all of the following hold:
        * The strings of the two lexical forms compare equal, character by character.
        * Either both or neither have language tags.
        * The language tags, if any, compare equal.
        * Either both or neither have datatype URIs.
        * The two datatype URIs, if any, compare equal, character by character."
        -- 6.5.1 Literal Equality (RDF: Concepts and Abstract Syntax)

    Example:
        ```python
        Literal("1", datatype=URIRef("foo")) == Literal("1", datatype=URIRef("foo"))
        # True
        Literal("1", datatype=URIRef("foo")) == Literal("1", datatype=URIRef("foo2"))
        # False

        Literal("1", datatype=URIRef("foo")) == Literal("2", datatype=URIRef("foo"))
        # False
        Literal("1", datatype=URIRef("foo")) == "asdf"
        # False

        from rdflib import XSD
        Literal('2007-01-01', datatype=XSD.date) == Literal('2007-01-01', datatype=XSD.date)
        # True
        Literal('2007-01-01', datatype=XSD.date) == date(2007, 1, 1)
        # False

        Literal("one", lang="en") == Literal("one", lang="en")
        # True
        Literal("hast", lang='en') == Literal("hast", lang='de')
        # False

        Literal("1", datatype=XSD.integer) == Literal(1)
        # True
        Literal("1", datatype=XSD.integer) == Literal("01", datatype=XSD.integer)
        # True
        ```
    """
    if self is other:
        return True
    if other is None:
        return False
    # Directly accessing the member is faster than the property.
    if isinstance(other, Literal):
        return (
            self._datatype == other._datatype
            and (self._language.lower() if self._language else None)
            == (other._language.lower() if other._language else None)
            and str.__eq__(self, other)
        )

    return False

__ge__

__ge__(other: Any) -> bool

Source code in rdflib/term.py

def __ge__(self, other: Any) -> bool:
    r = self.__gt__(other)
    if r:
        return True
    try:
        return self.eq(other)
    except TypeError:
        return NotImplemented

__getstate__

__getstate__() -> Tuple[None, Dict[str, Union[str, None]]]

Source code in rdflib/term.py

def __getstate__(self) -> Tuple[None, Dict[str, Union[str, None]]]:
    return (None, dict(language=self.language, datatype=self.datatype))

__gt__

__gt__(other: Any) -> bool

Implements the greater-than comparison for Literals.

This is the base method for ordering comparisons - other comparison methods delegate here.

Implements the ordering rules described in http://www.w3.org/TR/sparql11-query/#modOrderBy

In summary: 1. Literals with compatible data-types are ordered in value space 2. Incompatible datatypes are ordered by their datatype URIs 3. Literals with language tags are ordered by their language tags 4. Plain literals come before xsd:string literals 5. In the node order: None < BNode < URIRef < Literal

Example

from rdflib import XSD
from decimal import Decimal

# Comparing numeric literals in value space
Literal(1) > Literal(2)  # int/int
# False

Literal(2.0) > Literal(1)  # double/int
# True

Literal(Decimal("3.3")) > Literal(2.0)  # decimal/double
# True

Literal(Decimal("3.3")) < Literal(4.0)  # decimal/double
# True

# Comparing string literals
Literal('b') > Literal('a')  # plain lit/plain lit
# True

Literal('b') > Literal('a', datatype=XSD.string)  # plain lit/xsd:str
# True

# Incompatible datatypes ordered by DT
Literal(1) > Literal("2")  # int>string
# False

# Langtagged literals ordered by lang tag
Literal("a", lang="en") > Literal("a", lang="fr")
# False

Source code in rdflib/term.py

def __gt__(self, other: Any) -> bool:
    """Implements the greater-than comparison for Literals.

    This is the base method for ordering comparisons - other comparison methods delegate here.

    Implements the ordering rules described in http://www.w3.org/TR/sparql11-query/#modOrderBy

    In summary:
    1. Literals with compatible data-types are ordered in value space
    2. Incompatible datatypes are ordered by their datatype URIs
    3. Literals with language tags are ordered by their language tags
    4. Plain literals come before xsd:string literals
    5. In the node order: None < BNode < URIRef < Literal

    Example:
        ```python
        from rdflib import XSD
        from decimal import Decimal

        # Comparing numeric literals in value space
        Literal(1) > Literal(2)  # int/int
        # False

        Literal(2.0) > Literal(1)  # double/int
        # True

        Literal(Decimal("3.3")) > Literal(2.0)  # decimal/double
        # True

        Literal(Decimal("3.3")) < Literal(4.0)  # decimal/double
        # True

        # Comparing string literals
        Literal('b') > Literal('a')  # plain lit/plain lit
        # True

        Literal('b') > Literal('a', datatype=XSD.string)  # plain lit/xsd:str
        # True

        # Incompatible datatypes ordered by DT
        Literal(1) > Literal("2")  # int>string
        # False

        # Langtagged literals ordered by lang tag
        Literal("a", lang="en") > Literal("a", lang="fr")
        # False
        ```
    """
    if other is None:
        return True  # Everything is greater than None
    if isinstance(other, Literal):
        # Fast path for comparing numeric literals
        # that are not ill-typed and don't have a None value
        if (
            (
                self.datatype in _NUMERIC_LITERAL_TYPES
                and other.datatype in _NUMERIC_LITERAL_TYPES
            )
            and ((not self.ill_typed) and (not other.ill_typed))
            and (self.value is not None and other.value is not None)
        ):
            return self.value > other.value

        # plain-literals and xsd:string literals
        # are "the same"
        dtself = rdflib.util._coalesce(self.datatype, default=_XSD_STRING)
        dtother = rdflib.util._coalesce(other.datatype, default=_XSD_STRING)

        if dtself != dtother:
            if rdflib.DAWG_LITERAL_COLLATION:
                return NotImplemented
            else:
                return dtself > dtother

        if self.language != other.language:
            if not self.language:
                return False
            elif not other.language:
                return True
            else:
                return self.language > other.language

        if self.value is not None and other.value is not None:
            if type(self.value) in _TOTAL_ORDER_CASTERS:
                caster = _TOTAL_ORDER_CASTERS[type(self.value)]
                return caster(self.value) > caster(other.value)

            try:
                return self.value > other.value
            except TypeError:
                pass

        if str(self) != str(other):
            return str(self) > str(other)

        # same language, same lexical form, check real dt
        # plain-literals come before xsd:string!
        if self.datatype != other.datatype:
            if self.datatype is None:
                return False
            elif other.datatype is None:
                return True
            else:
                return self.datatype > other.datatype

        return False  # they are the same

    elif isinstance(other, Node):
        return True  # Literal are the greatest!
    else:
        return NotImplemented  # we can only compare to nodes

__hash__

__hash__() -> int

Hash function for Literals to enable their use as dictionary keys.

Example

from rdflib.namespace import XSD
a = {Literal('1', datatype=XSD.integer):'one'}
Literal('1', datatype=XSD.double) in a
# False

Notes

“Called for the key object for dictionary operations, and by the built-in function hash(). Should return a 32-bit integer usable as a hash value for dictionary operations. The only required property is that objects which compare equal have the same hash value; it is advised to somehow mix together (e.g., using exclusive or) the hash values for the components of the object that also play a part in comparison of objects.” – 3.4.1 Basic customization (Python)

“Two literals are equal if and only if all of the following hold: * The strings of the two lexical forms compare equal, character by character. * Either both or neither have language tags. * The language tags, if any, compare equal. * Either both or neither have datatype URIs. * The two datatype URIs, if any, compare equal, character by character.” – 6.5.1 Literal Equality (RDF: Concepts and Abstract Syntax)

Source code in rdflib/term.py

def __hash__(self) -> int:  # type: ignore[override]
    """Hash function for Literals to enable their use as dictionary keys.

    Example:
        ```python
        from rdflib.namespace import XSD
        a = {Literal('1', datatype=XSD.integer):'one'}
        Literal('1', datatype=XSD.double) in a
        # False
        ```

    Notes:
        "Called for the key object for dictionary operations,
        and by the built-in function hash(). Should return
        a 32-bit integer usable as a hash value for
        dictionary operations. The only required property
        is that objects which compare equal have the same
        hash value; it is advised to somehow mix together
        (e.g., using exclusive or) the hash values for the
        components of the object that also play a part in
        comparison of objects." -- 3.4.1 Basic customization (Python)

        "Two literals are equal if and only if all of the following hold:
        * The strings of the two lexical forms compare equal, character by character.
        * Either both or neither have language tags.
        * The language tags, if any, compare equal.
        * Either both or neither have datatype URIs.
        * The two datatype URIs, if any, compare equal, character by character."
        -- 6.5.1 Literal Equality (RDF: Concepts and Abstract Syntax)
    """
    # don't use super()... for efficiency reasons, see Identifier.__hash__
    res = str.__hash__(self)
    # Directly accessing the member is faster than the property.
    if self._language:
        res ^= hash(self._language.lower())
    if self._datatype is not None:
        res ^= hash(self._datatype)
    return res

__invert__

__invert__() -> Literal

Implements bitwise NOT operation for Literals with numeric values.

Example

# Bitwise NOT of a negative integer Literal
~(Literal(-1))
# rdflib.term.Literal('0', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# Using a string with a datatype
from rdflib.namespace import XSD
~(Literal("-1", datatype=XSD.integer))
# rdflib.term.Literal('0', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# This will raise a TypeError
~(Literal("1"))
# TypeError: Not a number; rdflib.term.Literal('1')

Source code in rdflib/term.py

def __invert__(self) -> Literal:
    """Implements bitwise NOT operation for Literals with numeric values.

    Example:
        ```python
        # Bitwise NOT of a negative integer Literal
        ~(Literal(-1))
        # rdflib.term.Literal('0', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # Using a string with a datatype
        from rdflib.namespace import XSD
        ~(Literal("-1", datatype=XSD.integer))
        # rdflib.term.Literal('0', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # This will raise a TypeError
        ~(Literal("1"))
        # TypeError: Not a number; rdflib.term.Literal('1')
        ```
    """
    if isinstance(self.value, (int, long_type, float)):
        # type error: Unsupported operand type for ~ ("float")
        return Literal(self.value.__invert__())  # type: ignore[operator] # FIXME
    else:
        raise TypeError(f"Not a number; {self!r}")

__le__

__le__(other: Any) -> bool

Less than or equal operator for Literals.

Example

from rdflib.namespace import XSD
Literal('2007-01-01T10:00:00', datatype=XSD.dateTime) <= Literal('2007-01-01T10:00:00', datatype=XSD.dateTime)
# True

Source code in rdflib/term.py

def __le__(self, other: Any) -> bool:
    """Less than or equal operator for Literals.

    Example:
        ```python
        from rdflib.namespace import XSD
        Literal('2007-01-01T10:00:00', datatype=XSD.dateTime) <= Literal('2007-01-01T10:00:00', datatype=XSD.dateTime)
        # True
        ```
    """
    r = self.__lt__(other)
    if r:
        return True
    try:
        return self.eq(other)
    except TypeError:
        return NotImplemented

__lt__

__lt__(other: Any) -> bool

Source code in rdflib/term.py

def __lt__(self, other: Any) -> bool:
    if other is None:
        return False  # Nothing is less than None
    if isinstance(other, Literal):
        try:
            return not self.__gt__(other) and not self.eq(other)
        except TypeError:
            return NotImplemented
    if isinstance(other, Node):
        return False  # all nodes are less-than Literals

    return NotImplemented

__neg__

__neg__() -> Literal

Implements unary negation for Literals with numeric values.

Example

# Negating an integer Literal
-Literal(1)
# rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# Negating a float Literal
-Literal(10.5)
# rdflib.term.Literal('-10.5', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#double'))

# Using a string with a datatype
from rdflib.namespace import XSD
-Literal("1", datatype=XSD.integer)
# rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# This will raise a TypeError
-Literal("1")
# TypeError: Not a number; rdflib.term.Literal('1')

Source code in rdflib/term.py

def __neg__(self) -> Literal:
    """Implements unary negation for Literals with numeric values.

    Example:
        ```python
        # Negating an integer Literal
        -Literal(1)
        # rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # Negating a float Literal
        -Literal(10.5)
        # rdflib.term.Literal('-10.5', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#double'))

        # Using a string with a datatype
        from rdflib.namespace import XSD
        -Literal("1", datatype=XSD.integer)
        # rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # This will raise a TypeError
        -Literal("1")
        # TypeError: Not a number; rdflib.term.Literal('1')
        ```
    """

    if isinstance(self.value, (int, long_type, float)):
        return Literal(self.value.__neg__())
    else:
        raise TypeError(f"Not a number; {self!r}")

__new__

__new__(lexical_or_value: Any, lang: Optional[str] = None, datatype: Optional[str] = None, normalize: Optional[bool] = None)

Create a new Literal instance.

Source code in rdflib/term.py

def __new__(
    cls,
    lexical_or_value: Any,
    lang: Optional[str] = None,
    datatype: Optional[str] = None,
    normalize: Optional[bool] = None,
):
    """Create a new Literal instance."""
    if lang == "":
        lang = None  # no empty lang-tags in RDF

    normalize = normalize if normalize is not None else rdflib.NORMALIZE_LITERALS

    if lang is not None and datatype is not None:
        raise TypeError(
            "A Literal can only have one of lang or datatype, "
            "per http://www.w3.org/TR/rdf-concepts/#section-Graph-Literal"
        )

    if lang is not None and not _is_valid_langtag(lang):
        raise ValueError(f"'{str(lang)}' is not a valid language tag!")

    if datatype is not None:
        datatype = URIRef(datatype)

    value = None
    ill_typed: Optional[bool] = None
    if isinstance(lexical_or_value, Literal):
        # create from another Literal instance

        lang = lang or lexical_or_value.language
        if datatype is not None:
            # override datatype
            value = _castLexicalToPython(lexical_or_value, datatype)
        else:
            datatype = lexical_or_value.datatype
            value = lexical_or_value.value

    elif isinstance(lexical_or_value, str) or isinstance(lexical_or_value, bytes):
        # passed a string
        # try parsing lexical form of datatyped literal
        value = _castLexicalToPython(lexical_or_value, datatype)
        if datatype is not None and datatype in _toPythonMapping:
            # datatype is a recognized datatype IRI:
            # https://www.w3.org/TR/rdf11-concepts/#dfn-recognized-datatype-iris
            dt_uri: URIRef = URIRef(datatype)
            checker = _check_well_formed_types.get(dt_uri, _well_formed_by_value)
            well_formed = checker(lexical_or_value, value)
            ill_typed = ill_typed or (not well_formed)
        if value is not None and normalize:
            _value, _datatype = _castPythonToLiteral(value, datatype)
            if _value is not None and _is_valid_unicode(_value):
                lexical_or_value = _value

    else:
        # passed some python object
        value = lexical_or_value
        _value, _datatype = _castPythonToLiteral(lexical_or_value, datatype)

        _datatype = None if _datatype is None else URIRef(_datatype)

        datatype = rdflib.util._coalesce(datatype, _datatype)
        if _value is not None:
            lexical_or_value = _value
        if datatype is not None:
            lang = None

    if isinstance(lexical_or_value, bytes):
        lexical_or_value = lexical_or_value.decode("utf-8")

    if datatype in (_XSD_NORMALISED_STRING, _XSD_TOKEN):
        lexical_or_value = _normalise_XSD_STRING(lexical_or_value)

    if datatype in (_XSD_TOKEN,):
        lexical_or_value = _strip_and_collapse_whitespace(lexical_or_value)

    try:
        inst = str.__new__(cls, lexical_or_value)
    except UnicodeDecodeError:
        inst = str.__new__(cls, lexical_or_value, "utf-8")

    inst._language = lang
    inst._datatype = datatype
    inst._value = value
    inst._ill_typed = ill_typed

    return inst

__pos__

__pos__() -> Literal

Implements unary plus operation for Literals with numeric values.

Example

# Applying unary plus to an integer Literal
+Literal(1)
# rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# Applying unary plus to a negative integer Literal
+Literal(-1)
# rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# Using a string with a datatype
from rdflib.namespace import XSD
+Literal("-1", datatype=XSD.integer)
# rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# This will raise a TypeError
+Literal("1")
# TypeError: Not a number; rdflib.term.Literal('1')

Source code in rdflib/term.py

def __pos__(self) -> Literal:
    """Implements unary plus operation for Literals with numeric values.

    Example:
        ```python
        # Applying unary plus to an integer Literal
        +Literal(1)
        # rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # Applying unary plus to a negative integer Literal
        +Literal(-1)
        # rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # Using a string with a datatype
        from rdflib.namespace import XSD
        +Literal("-1", datatype=XSD.integer)
        # rdflib.term.Literal('-1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # This will raise a TypeError
        +Literal("1")
        # TypeError: Not a number; rdflib.term.Literal('1')
        ```
    """
    if isinstance(self.value, (int, long_type, float)):
        return Literal(self.value.__pos__())
    else:
        raise TypeError(f"Not a number; {self!r}")

__reduce__

__reduce__() -> Tuple[Type[Literal], Tuple[str, Union[str, None], Union[str, None]]]

Source code in rdflib/term.py

def __reduce__(
    self,
) -> Tuple[Type[Literal], Tuple[str, Union[str, None], Union[str, None]]]:
    return (
        Literal,
        (str(self), self.language, self.datatype),
    )

__repr__

__repr__() -> str

Source code in rdflib/term.py

def __repr__(self) -> str:
    args = [str.__repr__(self)]
    if self.language is not None:
        args.append("lang=" + repr(self.language))
    if self.datatype is not None:
        args.append("datatype=" + repr(self.datatype))
    if self.__class__ == Literal:
        clsName = "rdflib.term.Literal"  # noqa: N806
    else:
        clsName = self.__class__.__name__  # noqa: N806
    return f"{clsName}({', '.join(args)})"

__setstate__

__setstate__(arg: Tuple[Any, Dict[str, Any]]) -> None

Source code in rdflib/term.py

def __setstate__(self, arg: Tuple[Any, Dict[str, Any]]) -> None:
    _, d = arg
    self._language = d["language"]
    self._datatype = d["datatype"]

__sub__

__sub__(val: Any) -> Literal

Implements subtraction between Literals or between a Literal and a Python object.

Example

from rdflib.namespace import XSD

# Basic numeric subtraction
Literal(2) - 1
# rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

Literal(1.1) - 1.0
# rdflib.term.Literal('0.10000000000000009', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#double'))

Literal(1.1) - 1
# rdflib.term.Literal('0.1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#decimal'))

Literal(1.1, datatype=XSD.float) - Literal(1.0, datatype=XSD.float)
# rdflib.term.Literal('0.10000000000000009', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#float'))

# This will raise a TypeError
Literal("1.1") - 1.0
# TypeError: Not a number; rdflib.term.Literal('1.1')

Literal(1.1, datatype=XSD.integer) - Literal(1.0, datatype=XSD.integer)
# rdflib.term.Literal('0.10000000000000009', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

# Handling dateTime/date/time based operations in Literals
a = Literal('2006-01-01T20:50:00', datatype=XSD.dateTime)
b = Literal('2006-02-01T20:50:00', datatype=XSD.dateTime)
(b - a)
# rdflib.term.Literal('P31D', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#duration'))

a = Literal('2006-07-01T20:52:00', datatype=XSD.dateTime)
b = Literal('2006-11-01T12:50:00', datatype=XSD.dateTime)
(a - b)
# rdflib.term.Literal('-P122DT15H58M', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#duration'))
(b - a)
# rdflib.term.Literal('P122DT15H58M', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#duration'))

Source code in rdflib/term.py

def __sub__(self, val: Any) -> Literal:
    """Implements subtraction between Literals or between a Literal and a Python object.

    Example:
        ```python
        from rdflib.namespace import XSD

        # Basic numeric subtraction
        Literal(2) - 1
        # rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        Literal(1.1) - 1.0
        # rdflib.term.Literal('0.10000000000000009', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#double'))

        Literal(1.1) - 1
        # rdflib.term.Literal('0.1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#decimal'))

        Literal(1.1, datatype=XSD.float) - Literal(1.0, datatype=XSD.float)
        # rdflib.term.Literal('0.10000000000000009', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#float'))

        # This will raise a TypeError
        Literal("1.1") - 1.0
        # TypeError: Not a number; rdflib.term.Literal('1.1')

        Literal(1.1, datatype=XSD.integer) - Literal(1.0, datatype=XSD.integer)
        # rdflib.term.Literal('0.10000000000000009', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

        # Handling dateTime/date/time based operations in Literals
        a = Literal('2006-01-01T20:50:00', datatype=XSD.dateTime)
        b = Literal('2006-02-01T20:50:00', datatype=XSD.dateTime)
        (b - a)
        # rdflib.term.Literal('P31D', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#duration'))

        a = Literal('2006-07-01T20:52:00', datatype=XSD.dateTime)
        b = Literal('2006-11-01T12:50:00', datatype=XSD.dateTime)
        (a - b)
        # rdflib.term.Literal('-P122DT15H58M', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#duration'))
        (b - a)
        # rdflib.term.Literal('P122DT15H58M', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#duration'))
        ```
    """
    # if no val is supplied, return this Literal
    if val is None:
        return self

    # convert the val to a Literal, if it isn't already one
    if not isinstance(val, Literal):
        val = Literal(val)

    if not getattr(self, "datatype"):
        raise TypeError(
            "Minuend Literal must have Numeric, Date, Datetime or Time datatype."
        )
    elif not getattr(val, "datatype"):
        raise TypeError(
            "Subtrahend Literal must have Numeric, Date, Datetime or Time datatype."
        )

    if (
        self.datatype in (_XSD_DATETIME, _XSD_DATE)
        and val.datatype in _TIME_DELTA_TYPES
    ):
        date1: Union[datetime, date] = self.toPython()
        duration: Union[Duration, timedelta] = val.toPython()
        difference = date1 - duration
        return Literal(difference, datatype=self.datatype)

    # if self is time based and value is duration
    elif self.datatype == _XSD_TIME and val.datatype in _TIME_DELTA_TYPES:
        selfv: time = self.toPython()
        valv: Union[Duration, timedelta] = val.toPython()
        sdt = datetime.combine(date(2000, 1, 1), selfv) - valv
        return Literal(sdt.time(), datatype=self.datatype)

    # if the datatypes are the same, just subtract the Python values and convert back
    if self.datatype == val.datatype:
        if self.datatype == _XSD_TIME:
            sdt = datetime.combine(date.today(), self.toPython())
            vdt = datetime.combine(date.today(), val.toPython())
            return Literal(sdt - vdt, datatype=_XSD_DURATION)
        else:
            return Literal(
                self.toPython() - val.toPython(),
                self.language,
                datatype=(
                    _XSD_DURATION
                    if self.datatype in (_XSD_DATETIME, _XSD_DATE, _XSD_TIME)
                    else self.datatype
                ),
            )

    # if the datatypes are not the same but are both numeric, subtract the Python values and strip off decimal junk
    # (i.e. tiny numbers (more than 17 decimal places) and trailing zeros) and return as a decimal
    elif (
        self.datatype in _NUMERIC_LITERAL_TYPES
        and val.datatype in _NUMERIC_LITERAL_TYPES
    ):
        return Literal(
            Decimal(
                f"{round(Decimal(self.toPython()) - Decimal(val.toPython()), 15):f}".rstrip(
                    "0"
                ).rstrip(
                    "."
                )
            ),
            datatype=_XSD_DECIMAL,
        )
    # in all other cases, perform string concatenation
    else:
        raise TypeError(
            f"Cannot subtract a Literal of datatype {str(val.datatype)} from a Literal of datatype {str(self.datatype)}"
        )

eq

eq(other: Any) -> bool

Compare the value of this literal with something else.

This comparison can be done in two ways:

1. With the value of another literal - comparisons are then done in literal “value space” according to the rules of XSD subtype-substitution/type-promotion

2. With a Python object:

3. string objects can be compared with plain-literals or those with datatype xsd:string
4. bool objects with xsd:boolean
5. int, long or float with numeric xsd types
6. date, time, datetime objects with xsd:date, xsd:time, xsd:datetime

Any other operations returns NotImplemented.

Source code in rdflib/term.py

def eq(self, other: Any) -> bool:
    """Compare the value of this literal with something else.

    This comparison can be done in two ways:

    1. With the value of another literal - comparisons are then done in literal "value space"
        according to the rules of XSD subtype-substitution/type-promotion

    2. With a Python object:
       * string objects can be compared with plain-literals or those with datatype xsd:string
       * bool objects with xsd:boolean
       * int, long or float with numeric xsd types
       * date, time, datetime objects with xsd:date, xsd:time, xsd:datetime

    Any other operations returns NotImplemented.
    """
    if isinstance(other, Literal):
        # Fast path for comparing numeric literals
        # that are not ill-typed and don't have a None value
        if (
            (
                self.datatype in _NUMERIC_LITERAL_TYPES
                and other.datatype in _NUMERIC_LITERAL_TYPES
            )
            and ((not self.ill_typed) and (not other.ill_typed))
            and (self.value is not None and other.value is not None)
        ):
            if self.value is not None and other.value is not None:
                return self.value == other.value
            else:
                if str.__eq__(self, other):
                    return True
                raise TypeError(
                    # TODO: Should this use repr strings in the error message?
                    "I cannot know that these two lexical forms do not map to the "
                    f"same value: {self} and {other}"
                )
        if (self.language or "").lower() != (other.language or "").lower():
            return False

        dtself = rdflib.util._coalesce(self.datatype, default=_XSD_STRING)
        dtother = rdflib.util._coalesce(other.datatype, default=_XSD_STRING)

        if dtself == _XSD_STRING and dtother == _XSD_STRING:
            # string/plain literals, compare on lexical form
            return str.__eq__(self, other)

        # XML can be compared to HTML, only if html5rdf is enabled
        if (
            (dtself in _XML_COMPARABLE and dtother in _XML_COMPARABLE)
            and
            # Ill-typed can be None if unknown, but we don't want it to be True.
            ((self.ill_typed is not True) and (other.ill_typed is not True))
            and (self.value is not None and other.value is not None)
        ):
            return _isEqualXMLNode(self.value, other.value)

        if dtself != dtother:
            if rdflib.DAWG_LITERAL_COLLATION:
                raise TypeError(
                    f"I don't know how to compare literals with datatypes {self.datatype} and {other.datatype}"
                )
            else:
                return False

        # matching non-string DTs now - do we compare values or
        # lexical form first?  comparing two ints is far quicker -
        # maybe there are counter examples

        if self.value is not None and other.value is not None:
            return self.value == other.value
        else:
            if str.__eq__(self, other):
                return True

            if self.datatype == _XSD_STRING:
                return False  # string value space=lexical space

            # matching DTs, but not matching, we cannot compare!
            raise TypeError(
                # TODO: Should this use repr strings in the error message?
                "I cannot know that these two lexical forms do not map to the same "
                f"value: {self} and {other}"
            )

    elif isinstance(other, Node):
        return False  # no non-Literal nodes are equal to a literal

    elif isinstance(other, str):
        # only plain-literals can be directly compared to strings

        # TODO: Is "blah"@en eq "blah" ?
        if self.language is not None:
            return False

        if self.datatype == _XSD_STRING or self.datatype is None:
            return str(self) == other

    elif isinstance(other, (int, long_type, float)):
        if self.datatype in _NUMERIC_LITERAL_TYPES:
            return self.value == other
    elif isinstance(other, (date, datetime, time)):
        if self.datatype in (_XSD_DATETIME, _XSD_DATE, _XSD_TIME):
            return self.value == other
    elif isinstance(other, (timedelta, Duration)):
        if self.datatype in (
            _XSD_DURATION,
            _XSD_DAYTIMEDURATION,
            _XSD_YEARMONTHDURATION,
        ):
            return self.value == other
    # NOTE for type ignore: bool is a subclass of int so this won't ever run.
    elif isinstance(other, bool):  # type: ignore[unreachable, unused-ignore]
        if self.datatype == _XSD_BOOLEAN:
            return self.value == other

    return NotImplemented

n3

n3(namespace_manager: Optional[NamespaceManager] = None) -> str

Returns a representation in the N3 format.

>>> Literal("foo").n3()
'"foo"'

Strings with newlines or triple-quotes:

>>> Literal("foo\nbar").n3()
'"""foo\nbar"""'
>>> Literal("''\'").n3()
'"\'\'\'"'
>>> Literal('"""').n3()
'"\\"\\"\\""'

Language:

>>> Literal("hello", lang="en").n3()
'"hello"@en'

Datatypes:

>>> Literal(1).n3()
'"1"^^<http://www.w3.org/2001/XMLSchema#integer>'
>>> Literal(1.0).n3()
'"1.0"^^<http://www.w3.org/2001/XMLSchema#double>'
>>> Literal(True).n3()
'"true"^^<http://www.w3.org/2001/XMLSchema#boolean>'

Datatype and language isn’t allowed (datatype takes precedence):

>>> Literal(1, lang="en").n3()
'"1"^^<http://www.w3.org/2001/XMLSchema#integer>'

Custom datatype:

>>> footype = URIRef("http://example.org/ns#foo")
>>> Literal("1", datatype=footype).n3()
'"1"^^<http://example.org/ns#foo>'

Passing a namespace-manager will use it to abbreviate datatype URIs:

>>> from rdflib import Graph
>>> Literal(1).n3(Graph().namespace_manager)
'"1"^^xsd:integer'

Source code in rdflib/term.py

def n3(self, namespace_manager: Optional[NamespaceManager] = None) -> str:
    r'''Returns a representation in the N3 format.

    ```python
    >>> Literal("foo").n3()
    '"foo"'

    ```

    Strings with newlines or triple-quotes:

    ```python
    >>> Literal("foo\nbar").n3()
    '"""foo\nbar"""'
    >>> Literal("''\'").n3()
    '"\'\'\'"'
    >>> Literal('"""').n3()
    '"\\"\\"\\""'

    ```

    Language:

    ```python
    >>> Literal("hello", lang="en").n3()
    '"hello"@en'

    ```

    Datatypes:

    ```python
    >>> Literal(1).n3()
    '"1"^^<http://www.w3.org/2001/XMLSchema#integer>'
    >>> Literal(1.0).n3()
    '"1.0"^^<http://www.w3.org/2001/XMLSchema#double>'
    >>> Literal(True).n3()
    '"true"^^<http://www.w3.org/2001/XMLSchema#boolean>'

    ```

    Datatype and language isn't allowed (datatype takes precedence):

    ```python
    >>> Literal(1, lang="en").n3()
    '"1"^^<http://www.w3.org/2001/XMLSchema#integer>'

    ```

    Custom datatype:

    ```python
    >>> footype = URIRef("http://example.org/ns#foo")
    >>> Literal("1", datatype=footype).n3()
    '"1"^^<http://example.org/ns#foo>'

    ```

    Passing a namespace-manager will use it to abbreviate datatype URIs:

    ```python
    >>> from rdflib import Graph
    >>> Literal(1).n3(Graph().namespace_manager)
    '"1"^^xsd:integer'

    ```
    '''
    if namespace_manager:
        return self._literal_n3(qname_callback=namespace_manager.normalizeUri)
    else:
        return self._literal_n3()

neq

neq(other: Any) -> bool

Source code in rdflib/term.py

def neq(self, other: Any) -> bool:
    return not self.eq(other)

normalize

normalize() -> Literal

Returns a new literal with a normalised lexical representation of this literal

>>> from rdflib import XSD
>>> Literal("01", datatype=XSD.integer, normalize=False).normalize()
rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

Illegal lexical forms for the datatype given are simply passed on

>>> Literal("a", datatype=XSD.integer, normalize=False)
rdflib.term.Literal('a', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

Source code in rdflib/term.py

def normalize(self) -> Literal:
    """
    Returns a new literal with a normalised lexical representation
    of this literal

    ```python
    >>> from rdflib import XSD
    >>> Literal("01", datatype=XSD.integer, normalize=False).normalize()
    rdflib.term.Literal('1', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

    ```

    Illegal lexical forms for the datatype given are simply passed on

    ```python
    >>> Literal("a", datatype=XSD.integer, normalize=False)
    rdflib.term.Literal('a', datatype=rdflib.term.URIRef('http://www.w3.org/2001/XMLSchema#integer'))

    ```
    """

    if self.value is not None:
        return Literal(self.value, datatype=self.datatype, lang=self.language)
    else:
        return self

toPython

toPython() -> Any

Returns an appropriate python datatype derived from this RDF Literal

Source code in rdflib/term.py

def toPython(self) -> Any:  # noqa: N802
    """
    Returns an appropriate python datatype derived from this RDF Literal
    """

    if self.value is not None:
        return self.value
    return self

Node

Bases: ABC

A Node in the Graph.

Methods:

• n3 –

Attributes:

• __slots__ –

__slots__ class-attribute instance-attribute

__slots__ = ()

n3 abstractmethod

n3(namespace_manager: Optional[NamespaceManager] = None) -> str

Source code in rdflib/term.py

@abc.abstractmethod
def n3(self, namespace_manager: Optional[NamespaceManager] = None) -> str: ...

RDFLibGenid

Bases: Genid

Attributes:

• __slots__ –

__slots__ class-attribute instance-attribute

__slots__ = ()

URIRef

Bases: IdentifiedNode

RDF 1.1’s IRI Section

Terminology

Documentation on RDF outside of RDFLib uses the term IRI or URI whereas this class is called URIRef. This is because it was made when the first version of the RDF specification was current, and it used the term URIRef, see RDF 1.0 URIRef

An IRI (Internationalized Resource Identifier) within an RDF graph is a Unicode string that conforms to the syntax defined in RFC 3987.

IRIs in the RDF abstract syntax MUST be absolute, and MAY contain a fragment identifier.

IRIs are a generalization of URIs [RFC3986] that permits a wider range of Unicode characters.

Methods:

• __add__ –
• __mod__ –
• __new__ –
• __radd__ –
• __reduce__ –
• __repr__ –
• de_skolemize –

  Create a Blank Node from a skolem URI, in accordance

• defrag –
• n3 –

  This will do a limited check for valid URIs,

Attributes:

• __invert__ (Callable[[URIRef], InvPath]) –
• __neg__ (Callable[[URIRef], NegatedPath]) –
• __or__ (Callable[[URIRef, Union[URIRef, Path]], AlternativePath]) –
• __slots__ –
• __truediv__ (Callable[[URIRef, Union[URIRef, Path]], SequencePath]) –
• fragment (str) –

  Return the URL Fragment

__invert__ instance-attribute

__invert__: Callable[[URIRef], InvPath]

__neg__ instance-attribute

__neg__: Callable[[URIRef], NegatedPath]

__or__ instance-attribute

__or__: Callable[[URIRef, Union[URIRef, Path]], AlternativePath]

__slots__ class-attribute instance-attribute

__slots__ = ()

__truediv__ instance-attribute

__truediv__: Callable[[URIRef, Union[URIRef, Path]], SequencePath]

fragment property

fragment: str

Return the URL Fragment

>>> URIRef("http://example.com/some/path/#some-fragment").fragment
'some-fragment'
>>> URIRef("http://example.com/some/path/").fragment
''

__add__

__add__(other) -> URIRef

Source code in rdflib/term.py

def __add__(self, other) -> URIRef:
    return self.__class__(str(self) + other)

__mod__

__mod__(other) -> URIRef

Source code in rdflib/term.py

def __mod__(self, other) -> URIRef:
    return self.__class__(str(self) % other)

__new__

__new__(value: str, base: Optional[str] = None)

Source code in rdflib/term.py

def __new__(cls, value: str, base: Optional[str] = None):
    if base is not None:
        ends_in_hash = value.endswith("#")
        # type error: Argument "allow_fragments" to "urljoin" has incompatible type "int"; expected "bool"
        value = urljoin(base, value, allow_fragments=1)  # type: ignore[arg-type]
        if ends_in_hash:
            if not value.endswith("#"):
                value += "#"

    if not _is_valid_uri(value):
        logger.warning(
            f"{value} does not look like a valid URI, trying to serialize this will break."
        )

    try:
        rt = str.__new__(cls, value)
    except UnicodeDecodeError:
        # type error: No overload variant of "__new__" of "str" matches argument types "Type[URIRef]", "str", "str"
        rt = str.__new__(cls, value, "utf-8")  # type: ignore[call-overload]
    return rt

__radd__

__radd__(other) -> URIRef

Source code in rdflib/term.py

def __radd__(self, other) -> URIRef:
    return self.__class__(other + str(self))

__reduce__

__reduce__() -> Tuple[Type[URIRef], Tuple[str]]

Source code in rdflib/term.py

def __reduce__(self) -> Tuple[Type[URIRef], Tuple[str]]:
    return (URIRef, (str(self),))

__repr__

__repr__() -> str

Source code in rdflib/term.py

def __repr__(self) -> str:
    if self.__class__ is URIRef:
        clsName = "rdflib.term.URIRef"  # noqa: N806
    else:
        clsName = self.__class__.__name__  # noqa: N806

    return f"{clsName}({str.__repr__(self)})"

de_skolemize

de_skolemize() -> BNode

Create a Blank Node from a skolem URI, in accordance with http://www.w3.org/TR/rdf11-concepts/#section-skolemization. This function accepts only rdflib type skolemization, to provide a round-tripping within the system.

Added in version 4.0

Source code in rdflib/term.py

def de_skolemize(self) -> BNode:
    """Create a Blank Node from a skolem URI, in accordance
    with http://www.w3.org/TR/rdf11-concepts/#section-skolemization.
    This function accepts only rdflib type skolemization, to provide
    a round-tripping within the system.

    Added in version 4.0
    """
    if isinstance(self, RDFLibGenid):
        parsed_uri = urlparse(f"{self}")
        return BNode(value=parsed_uri.path[len(rdflib_skolem_genid) :])
    elif isinstance(self, Genid):
        bnode_id = f"{self}"
        if bnode_id in skolems:
            return skolems[bnode_id]
        else:
            retval = BNode()
            skolems[bnode_id] = retval
            return retval
    else:
        raise Exception(f"<{self}> is not a skolem URI")

defrag

defrag() -> URIRef

Source code in rdflib/term.py

def defrag(self) -> URIRef:
    if "#" in self:
        url, frag = urldefrag(self)
        return URIRef(url)
    else:
        return self

n3

n3(namespace_manager: Optional[NamespaceManager] = None) -> str

This will do a limited check for valid URIs, essentially just making sure that the string includes no illegal characters (<, >, ", {, }, |, \,, ^`)

Parameters:

• namespace_manager

  (Optional[NamespaceManager], default: None ) –

  if not None, will be used to make up a prefixed name

Source code in rdflib/term.py

def n3(self, namespace_manager: Optional[NamespaceManager] = None) -> str:
    """This will do a limited check for valid URIs,
    essentially just making sure that the string includes no illegal
    characters (`<, >, ", {, }, |, \\, `, ^`)

    Args:
        namespace_manager: if not None, will be used to make up a prefixed name
    """

    if not _is_valid_uri(self):
        raise Exception(
            f'"{self}" does not look like a valid URI, I cannot serialize this as N3/Turtle. Perhaps you wanted to urlencode it?'
        )

    if namespace_manager:
        return namespace_manager.normalizeUri(self)
    else:
        return f"<{self}>"

Variable

Bases: Identifier

A Variable - this is used for querying, or in Formula aware graphs, where Variables can be stored

Methods:

• __new__ –
• __reduce__ –
• __repr__ –
• n3 –
• toPython –

Attributes:

• __slots__ –

__slots__ class-attribute instance-attribute

__slots__ = ()

__new__

__new__(value: str)

Source code in rdflib/term.py

def __new__(cls, value: str):
    if len(value) == 0:
        raise Exception("Attempted to create variable with empty string as name!")
    if value[0] == "?":
        value = value[1:]
    return str.__new__(cls, value)

__reduce__

__reduce__() -> Tuple[Type[Variable], Tuple[str]]

Source code in rdflib/term.py

def __reduce__(self) -> Tuple[Type[Variable], Tuple[str]]:
    return (Variable, (str(self),))

__repr__

__repr__() -> str

Source code in rdflib/term.py

def __repr__(self) -> str:
    if self.__class__ is Variable:
        clsName = "rdflib.term.Variable"  # noqa: N806
    else:
        clsName = self.__class__.__name__  # noqa: N806

    return f"{clsName}({str.__repr__(self)})"

n3

n3(namespace_manager: Optional[NamespaceManager] = None) -> str

Source code in rdflib/term.py

def n3(self, namespace_manager: Optional[NamespaceManager] = None) -> str:
    return "?" + self

toPython

toPython() -> str

Source code in rdflib/term.py

def toPython(self) -> str:  # noqa: N802
    return "?" + self

bind

bind(datatype: str, pythontype: Type[Any], constructor: Optional[Callable[[str], Any]] = None, lexicalizer: Optional[Callable[[Any], Union[str, bytes]]] = None, datatype_specific: bool = False) -> None

register a new datatype<->pythontype binding

Parameters:

• constructor

  (Optional[Callable[[str], Any]], default: None ) –

  An optional function for converting lexical forms into a Python instances, if not given the pythontype is used directly

• lexicalizer

  (Optional[Callable[[Any], Union[str, bytes]]], default: None ) –

  An optional function for converting python objects to lexical form, if not given object.str is used

• datatype_specific

  (bool, default: False ) –

  Makes the lexicalizer function be accessible from the pair (pythontype, datatype) if set to True or from the pythontype otherwise. False by default

Source code in rdflib/term.py

def bind(
    datatype: str,
    pythontype: Type[Any],
    constructor: Optional[Callable[[str], Any]] = None,
    lexicalizer: Optional[Callable[[Any], Union[str, bytes]]] = None,
    datatype_specific: bool = False,
) -> None:
    """
    register a new datatype<->pythontype binding

    Args:
        constructor: An optional function for converting lexical forms
            into a Python instances, if not given the pythontype
            is used directly
        lexicalizer: An optional function for converting python objects to
            lexical form, if not given object.__str__ is used
        datatype_specific: Makes the lexicalizer function be accessible
            from the pair (pythontype, datatype) if set to True
            or from the pythontype otherwise. False by default
    """
    if datatype_specific and datatype is None:
        raise Exception("No datatype given for a datatype-specific binding")

    if datatype in _toPythonMapping:
        logger.warning(f"datatype '{datatype}' was already bound. Rebinding.")

    if constructor is None:
        constructor = pythontype
    _toPythonMapping[datatype] = constructor
    if datatype_specific:
        _SpecificPythonToXSDRules.append(((pythontype, datatype), lexicalizer))
    else:
        _GenericPythonToXSDRules.append((pythontype, (lexicalizer, datatype)))