Add typing to rdflib.term

This adds as much typing as possible to `rdflib.term`.

Other changes:
- Added back `warn_unused_ignores`. I actually thought this was enabled
  but I forgot I disabled it because of some issue on python 3.10.
- Disabled `warn_unused_ignores` only for `rdflib.plugin`. There is an
  ignore in this module which is not needed on python 3.10, this is the
  most targetted way to avoid having that fail the type checking that I
  can think of for now.
- Removed unused type ignores.

This changeset includes no runtime changes.

rdflib/graph.py

@@ -1223,7 +1223,7 @@ def parse(
         parser = plugin.get(format, Parser)()
         try:
             # TODO FIXME: Parser.parse should have **kwargs argument.
-            parser.parse(source, self, **args)  # type: ignore[call-arg]
+            parser.parse(source, self, **args)
         except SyntaxError as se:
             if could_not_guess_format:
                 raise ParserError(
@@ -1624,7 +1624,7 @@ def __contains__(self, triple_or_quad):
             return True
         return False
 
-    def add(self, triple_or_quad: Union[Tuple[Node, Node, Node, Optional[Any]], Tuple[Node, Node, Node]]) -> "ConjunctiveGraph":  # type: ignore[override]
+    def add(self, triple_or_quad: Union[Tuple[Node, Node, Node, Optional[Any]], Tuple[Node, Node, Node]]) -> "ConjunctiveGraph":
         """
         Add a triple or quad to the store.
 

rdflib/plugins/parsers/rdfxml.py

@@ -474,7 +474,7 @@ def property_element_start(self, name, qname, attrs):
                     o = URIRef(atts[att])
                 else:
                     if datatype is not None:
-                        language = None  # type: ignore[unreachable]
+                        language = None
                     o = Literal(atts[att], language, datatype)
 
                 if object is None:

rdflib/plugins/serializers/trig.py

@@ -90,6 +90,7 @@ def serialize(
             if self.default_context and store.identifier == self.default_context:
                 self.write(self.indent() + "\n{")
             else:
+                iri: Optional[str]
                 if isinstance(store.identifier, BNode):
                     iri = store.identifier.n3()
                 else:

rdflib/plugins/sparql/results/xmlresults.py

@@ -61,11 +61,19 @@ def __init__(self, source, content_type: Optional[str] = None):
             for result in results:  # type: ignore[union-attr]
                 r = {}
                 for binding in result:
-                    r[Variable(binding.get("name"))] = parseTerm(binding[0])
+                    # type error: error: Argument 1 to "Variable" has incompatible type "Union[str, None, Any]"; expected "str"
+                    # NOTE on type error: Element.get() can return None, and
+                    # this will invariably fail if passed into Variable
+                    # constructor as value
+                    r[Variable(binding.get("name"))] = parseTerm(binding[0])  # type: ignore[arg-type] # FIXME
                 self.bindings.append(r)
 
             self.vars = [
-                Variable(x.get("name"))
+                # type error: Argument 1 to "Variable" has incompatible type "Optional[str]"; expected "str"
+                # NOTE on type error: Element.get() can return None, and this
+                # will invariably fail if passed into Variable constructor as
+                # value
+                Variable(x.get("name"))  # type: ignore[arg-type] # FIXME
                 for x in tree.findall(
                     "./%shead/%svariable" % (RESULTS_NS_ET, RESULTS_NS_ET)
                 )

rdflib/plugins/stores/sparqlstore.py

@@ -37,7 +37,7 @@ def _node_to_sparql(node) -> str:
     return node.n3()
 
 
-class SPARQLStore(SPARQLConnector, Store):  # type: ignore[misc]
+class SPARQLStore(SPARQLConnector, Store):
     """An RDFLib store around a SPARQL endpoint
 
     This is context-aware and should work as expected
@@ -543,7 +543,7 @@ def open(self, configuration: Union[str, Tuple[str, str]], create=False):
         Graph("SPARQLStore"), can set the required parameters
         """
         if type(configuration) == str:
-            self.query_endpoint = configuration  # type: ignore[assignment]
+            self.query_endpoint = configuration
         elif type(configuration) == tuple:
             self.query_endpoint = configuration[0]
             self.update_endpoint = configuration[1]

rdflib/store.py

@@ -380,7 +380,7 @@ def namespaces(self):
         # See https://stackoverflow.com/q/13243766 and
         # https://www.python.org/dev/peps/pep-0255/#why-a-new-keyword-for-yield-why-not-a-builtin-function-instead
         if False:
-            yield None  # type: ignore[unreachable]
+            yield None
 
     # Optional Transactional methods