Specify Optional parameters in Graph.triples_choices (#3075)

* Specify `Optional` parameters in `Graph.triples_choices`

The two non-list parameters can be `None`, but this is not reflected in
the type hint.

Also introduces a type alias to simplify method signatures.

* style: remove unused imports

---------

Co-authored-by: Nicholas Car <[email protected]>
Co-authored-by: Edmond Chuc <[email protected]>
Co-authored-by: Edmond Chuc <[email protected]>

Author: 3 people

rdflib/graph.py

@@ -355,6 +355,11 @@
 _TripleOrQuadSelectorType = Union["_TripleSelectorType", "_QuadSelectorType"]
 _TriplePathType = Tuple["_SubjectType", Path, "_ObjectType"]
 _TripleOrTriplePathType = Union["_TripleType", "_TriplePathType"]
+_TripleChoiceType = Union[
+    Tuple[List[_SubjectType], Optional[_PredicateType], Optional[_ObjectType]],
+    Tuple[Optional[_SubjectType], List[_PredicateType], Optional[_ObjectType]],
+    Tuple[Optional[_SubjectType], Optional[_PredicateType], List[_ObjectType]],
+]
 
 _GraphT = TypeVar("_GraphT", bound="Graph")
 _ConjunctiveGraphT = TypeVar("_ConjunctiveGraphT", bound="ConjunctiveGraph")
@@ -994,11 +999,7 @@ def predicate_objects(
 
     def triples_choices(
         self,
-        triple: Union[
-            Tuple[List[_SubjectType], _PredicateType, _ObjectType],
-            Tuple[_SubjectType, List[_PredicateType], _ObjectType],
-            Tuple[_SubjectType, _PredicateType, List[_ObjectType]],
-        ],
+        triple: _TripleChoiceType,
         context: Optional[_ContextType] = None,
     ) -> Generator[_TripleType, None, None]:
         subject, predicate, object_ = triple
@@ -2196,11 +2197,7 @@ def quads(
 
     def triples_choices(
         self,
-        triple: Union[
-            Tuple[List[_SubjectType], _PredicateType, _ObjectType],
-            Tuple[_SubjectType, List[_PredicateType], _ObjectType],
-            Tuple[_SubjectType, _PredicateType, List[_ObjectType]],
-        ],
+        triple: _TripleChoiceType,
         context: Optional[_ContextType] = None,
     ) -> Generator[_TripleType, None, None]:
         """Iterate over all the triples in the entire conjunctive graph"""
@@ -2946,11 +2943,7 @@ def __isub__(self: _GraphT, other: Iterable[_TripleType]) -> NoReturn:
 
     def triples_choices(
         self,
-        triple: Union[
-            Tuple[List[_SubjectType], _PredicateType, _ObjectType],
-            Tuple[_SubjectType, List[_PredicateType], _ObjectType],
-            Tuple[_SubjectType, _PredicateType, List[_ObjectType]],
-        ],
+        triple: _TripleChoiceType,
         context: Optional[_ContextType] = None,
     ) -> Generator[_TripleType, None, None]:
         subject, predicate, object_ = triple

rdflib/plugins/stores/sparqlstore.py

@@ -35,6 +35,7 @@
         _TripleType,
         _ContextType,
         _QuadType,
+        _TripleChoiceType,
         _TriplePatternType,
         _SubjectType,
         _PredicateType,
@@ -367,11 +368,7 @@ def triples(  # type: ignore[override]
 
     def triples_choices(
         self,
-        _: Tuple[
-            Union[_SubjectType, List[_SubjectType]],
-            Union[_PredicateType, List[_PredicateType]],
-            Union[_ObjectType, List[_ObjectType]],
-        ],
+        _: _TripleChoiceType,
         context: Optional[_ContextType] = None,
     ) -> Generator[
         Tuple[

rdflib/store.py

@@ -36,7 +36,6 @@
     Generator,
     Iterable,
     Iterator,
-    List,
     Mapping,
     Optional,
     Tuple,
@@ -49,10 +48,8 @@
     from rdflib.graph import (
         Graph,
         _ContextType,
-        _ObjectType,
-        _PredicateType,
         _QuadType,
-        _SubjectType,
+        _TripleChoiceType,
         _TriplePatternType,
         _TripleType,
     )
@@ -281,11 +278,7 @@ def remove(
 
     def triples_choices(
         self,
-        triple: Union[
-            Tuple[List[_SubjectType], _PredicateType, _ObjectType],
-            Tuple[_SubjectType, List[_PredicateType], _ObjectType],
-            Tuple[_SubjectType, _PredicateType, List[_ObjectType]],
-        ],
+        triple: _TripleChoiceType,
         context: Optional[_ContextType] = None,
     ) -> Generator[
         Tuple[