Resolve some Pyright type errors in Span/ReadableSpan and utility stubs

Signed-off-by: emdneto <9735060+emdneto@users.noreply.github.com>

Author: emdneto

CHANGELOG.md

@@ -22,6 +22,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#4935](https://github.com/open-telemetry/opentelemetry-python/pull/4935))
 - `opentelemetry-sdk`: upgrade vendored OTel configuration schema from v1.0.0-rc.3 to v1.0.0
   ([#4965](https://github.com/open-telemetry/opentelemetry-python/pull/4965))
+- Resolve some Pyright type errors in Span/ReadableSpan and utility stubs
+  ([#4965](https://github.com/open-telemetry/opentelemetry-python/pull/4965))
 
 ## Version 1.40.0/0.61b0 (2026-03-04)
 

opentelemetry-sdk/src/opentelemetry/sdk/trace/__init__.py

@@ -153,6 +153,7 @@ def force_flush(self, timeout_millis: int = 30000) -> bool:
         Returns:
             False if the timeout is exceeded, True otherwise.
         """
+        return True
 
 
 # Temporary fix until https://github.com/PyCQA/pylint/issues/4098 is resolved
@@ -251,9 +252,13 @@ def __init__(self, num_threads: int = 2):
             # Only the main thread is kept in forked processed, the executor
             # needs to be re-instantiated to get a fresh pool of threads:
             weak_reinit = weakref.WeakMethod(self._init_executor)
-            os.register_at_fork(
-                after_in_child=lambda: weak_reinit()(num_threads)
-            )
+
+            def _after_in_child() -> None:
+                reinit = weak_reinit()
+                if reinit is not None:
+                    reinit(num_threads)
+
+            os.register_at_fork(after_in_child=_after_in_child)
 
     def _init_executor(self, num_threads: int) -> None:
         self._executor = concurrent.futures.ThreadPoolExecutor(
@@ -466,7 +471,7 @@ def dropped_links(self) -> int:
     def name(self) -> str:
         return self._name
 
-    def get_span_context(self):
+    def get_span_context(self) -> Optional[trace_api.SpanContext]:
         return self._context
 
     @property
@@ -880,8 +885,8 @@ def _new_links(self, links: Sequence[trace_api.Link]):
 
         return BoundedList.from_seq(self._limits.max_links, valid_links)
 
-    def get_span_context(self):
-        return self._context
+    def get_span_context(self) -> trace_api.SpanContext:
+        return typing.cast(trace_api.SpanContext, self._context)
 
     def set_attributes(
         self, attributes: Mapping[str, types.AttributeValue]
@@ -1047,7 +1052,7 @@ def __exit__(
                 self.set_status(
                     Status(
                         status_code=StatusCode.ERROR,
-                        description=f"{exc_type.__name__}: {exc_val}",
+                        description=(f"{type(exc_val).__name__}: {exc_val}"),
                     )
                 )
 
@@ -1182,6 +1187,7 @@ def start_span(  # pylint: disable=too-many-locals
         record_exception: bool = True,
         set_status_on_exception: bool = True,
     ) -> trace_api.Span:
+        links = links or ()
         parent_span_context = trace_api.get_current_span(
             context
         ).get_span_context()

opentelemetry-sdk/src/opentelemetry/sdk/util/__init__.pyi

@@ -17,6 +17,7 @@ from typing import (
     Iterator,
     Mapping,
     MutableMapping,
+    Optional,
     Sequence,
     TypeVar,
     overload,
@@ -42,7 +43,7 @@ class BoundedList(Sequence[_T]):
     """
 
     dropped: int
-    def __init__(self, maxlen: int): ...
+    def __init__(self, maxlen: Optional[int]): ...
     def insert(self, index: int, value: _T) -> None: ...
     @overload
     def __getitem__(self, i: int) -> _T: ...
@@ -52,7 +53,9 @@ class BoundedList(Sequence[_T]):
     def append(self, item: _T) -> None: ...
     def extend(self, seq: Sequence[_T]) -> None: ...
     @classmethod
-    def from_seq(cls, maxlen: int, seq: Iterable[_T]) -> BoundedList[_T]: ...  # pylint: disable=undefined-variable
+    def from_seq(
+        cls, maxlen: Optional[int], seq: Iterable[_T]
+    ) -> BoundedList[_T]: ...  # pylint: disable=undefined-variable
 
 class BoundedDict(MutableMapping[_KT, _VT]):
     """An ordered dict with a fixed max capacity.

pyproject.toml

@@ -113,8 +113,6 @@ exclude = [
   "opentelemetry-sdk/tests",
   "opentelemetry-sdk/src/opentelemetry/sdk/_events",
   "opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/",
-  "opentelemetry-sdk/src/opentelemetry/sdk/trace/__init__.py",
-  "opentelemetry-sdk/src/opentelemetry/sdk/_configuration/models.py",
   "opentelemetry-sdk/benchmarks",
   "exporter/opentelemetry-exporter-otlp-proto-grpc/tests",
 ]