Python: Use pass instead of ... for empty class bodies and methods in workflows

python/CODING_STANDARD.md

@@ -145,6 +145,39 @@ user_msg = UserMessage(content="Hello, world!")
 asst_msg = AssistantMessage(content="Hello, world!")
 ```
 
+### Empty Method Bodies
+
+Use `pass` for empty method bodies rather than `...` (Ellipsis). The `...` literal should be reserved for `@overload` stubs and `= ...` default argument sentinels, where it carries idiomatic meaning.
+
+```python
+# ✅ Preferred - concrete no-op method body
+async def on_checkpoint_restore(self, state: dict[str, Any]) -> None:
+    """Hook called when the workflow is restored from a checkpoint."""
+    pass
+
+# ✅ Preferred - Protocol method stub
+class CheckpointStorage(Protocol):
+    async def save(self, checkpoint: WorkflowCheckpoint) -> CheckpointID:
+        """Save a checkpoint and return its ID."""
+        pass
+
+# ✅ Preferred - abstract method
+@abstractmethod
+async def plan(self, context: Context) -> Message:
+    """Create a plan for the task."""
+    raise NotImplementedError
+
+# ✅ Acceptable - @overload stubs and default argument sentinels use ...
+@overload
+def run(self, stream: Literal[True]) -> ResponseStream: ...
+@overload
+def run(self, stream: Literal[False] = ...) -> Response: ...
+
+# ❌ Avoid - ... in concrete or Protocol method bodies
+async def on_checkpoint_restore(self, state: dict[str, Any]) -> None:
+    ...
+```
+
 ### Import Structure
 
 The package follows a flat import structure:

python/packages/core/agent_framework/_workflows/_checkpoint.py

@@ -128,7 +128,7 @@ async def save(self, checkpoint: WorkflowCheckpoint) -> CheckpointID:
         Returns:
             The unique ID of the saved checkpoint.
         """
-        ...
+        pass
 
     async def load(self, checkpoint_id: CheckpointID) -> WorkflowCheckpoint:
         """Load a checkpoint by ID.
@@ -142,7 +142,7 @@ async def load(self, checkpoint_id: CheckpointID) -> WorkflowCheckpoint:
         Raises:
             WorkflowCheckpointException: If no checkpoint with the given ID exists.
         """
-        ...
+        pass
 
     async def list_checkpoints(self, *, workflow_name: str) -> list[WorkflowCheckpoint]:
         """List checkpoint objects for a given workflow name.
@@ -153,7 +153,7 @@ async def list_checkpoints(self, *, workflow_name: str) -> list[WorkflowCheckpoi
         Returns:
             A list of WorkflowCheckpoint objects for the specified workflow name.
         """
-        ...
+        pass
 
     async def delete(self, checkpoint_id: CheckpointID) -> bool:
         """Delete a checkpoint by ID.
@@ -164,7 +164,7 @@ async def delete(self, checkpoint_id: CheckpointID) -> bool:
         Returns:
             True if the checkpoint was successfully deleted, False if no checkpoint with the given ID exists.
         """
-        ...
+        pass
 
     async def get_latest(self, *, workflow_name: str) -> WorkflowCheckpoint | None:
         """Get the latest checkpoint for a given workflow name.
@@ -175,7 +175,7 @@ async def get_latest(self, *, workflow_name: str) -> WorkflowCheckpoint | None:
         Returns:
             The latest WorkflowCheckpoint object for the specified workflow name, or None if no checkpoints exist.
         """
-        ...
+        pass
 
     async def list_checkpoint_ids(self, *, workflow_name: str) -> list[CheckpointID]:
         """List checkpoint IDs for a given workflow name.
@@ -186,7 +186,7 @@ async def list_checkpoint_ids(self, *, workflow_name: str) -> list[CheckpointID]
         Returns:
             A list of checkpoint IDs for the specified workflow name.
         """
-        ...
+        pass
 
 
 class InMemoryCheckpointStorage:

python/packages/core/agent_framework/_workflows/_executor.py

@@ -513,7 +513,7 @@ async def on_checkpoint_restore(self, state: dict[str, Any]) -> None:
         Args:
             state: The state dictionary that was saved during checkpointing.
         """
-        ...
+        pass
 
 
 # endregion: Executor

python/packages/core/agent_framework/_workflows/_runner_context.py

@@ -105,51 +105,51 @@ async def send_message(self, WorkflowMessage: WorkflowMessage) -> None:
         Args:
             WorkflowMessage: The WorkflowMessage to be sent.
         """
-        ...
+        pass
 
     async def drain_messages(self) -> dict[str, list[WorkflowMessage]]:
         """Drain all messages from the context.
 
         Returns:
             A dictionary mapping executor IDs to lists of messages.
         """
-        ...
+        pass
 
     async def has_messages(self) -> bool:
         """Check if there are any messages in the context.
 
         Returns:
             True if there are messages, False otherwise.
         """
-        ...
+        pass
 
     async def add_event(self, event: WorkflowEvent) -> None:
         """Add an event to the execution context.
 
         Args:
             event: The event to be added.
         """
-        ...
+        pass
 
     async def drain_events(self) -> list[WorkflowEvent]:
         """Drain all events from the context.
 
         Returns:
             A list of events that were added to the context.
         """
-        ...
+        pass
 
     async def has_events(self) -> bool:
         """Check if there are any events in the context.
 
         Returns:
             True if there are events, False otherwise.
         """
-        ...
+        pass
 
     async def next_event(self) -> WorkflowEvent:  # pragma: no cover - interface only
         """Wait for and return the next event emitted by the workflow run."""
-        ...
+        pass
 
     # Checkpointing capability
     def has_checkpointing(self) -> bool:
@@ -158,39 +158,39 @@ def has_checkpointing(self) -> bool:
         Returns:
             True if checkpointing is supported, False otherwise.
         """
-        ...
+        pass
 
     def set_runtime_checkpoint_storage(self, storage: CheckpointStorage) -> None:
         """Set runtime checkpoint storage to override build-time configuration.
 
         Args:
             storage: The checkpoint storage to use for this run.
         """
-        ...
+        pass
 
     def clear_runtime_checkpoint_storage(self) -> None:
         """Clear runtime checkpoint storage override."""
-        ...
+        pass
 
     def reset_for_new_run(self) -> None:
         """Reset the context for a new workflow run."""
-        ...
+        pass
 
     def set_streaming(self, streaming: bool) -> None:
         """Set whether agents should stream incremental updates.
 
         Args:
             streaming: True for streaming mode (stream=True), False for non-streaming (stream=False).
         """
-        ...
+        pass
 
     def is_streaming(self) -> bool:
         """Check if the workflow is in streaming mode.
 
         Returns:
             True if streaming mode is enabled, False otherwise.
         """
-        ...
+        pass
 
     async def create_checkpoint(
         self,
@@ -217,7 +217,7 @@ async def create_checkpoint(
         Returns:
             The ID of the created checkpoint.
         """
-        ...
+        pass
 
     async def load_checkpoint(self, checkpoint_id: CheckpointID) -> WorkflowCheckpoint | None:
         """Load a checkpoint without mutating the current context state.
@@ -228,23 +228,23 @@ async def load_checkpoint(self, checkpoint_id: CheckpointID) -> WorkflowCheckpoi
         Returns:
             The loaded checkpoint, or None if it does not exist.
         """
-        ...
+        pass
 
     async def apply_checkpoint(self, checkpoint: WorkflowCheckpoint) -> None:
         """Apply a checkpoint to the current context, mutating its state.
 
         Args:
             checkpoint: The checkpoint whose state is to be applied.
         """
-        ...
+        pass
 
     async def add_request_info_event(self, event: WorkflowEvent[Any]) -> None:
         """Add a request_info event to the context and track it for correlation.
 
         Args:
             event: The WorkflowEvent with type='request_info' to be added.
         """
-        ...
+        pass
 
     async def send_request_info_response(self, request_id: str, response: Any) -> None:
         """Send a response correlated to a pending request.
@@ -253,15 +253,15 @@ async def send_request_info_response(self, request_id: str, response: Any) -> No
             request_id: The ID of the original request.
             response: The response data to be sent.
         """
-        ...
+        pass
 
     async def get_pending_request_info_events(self) -> dict[str, WorkflowEvent[Any]]:
         """Get the mapping of request IDs to their corresponding request_info events.
 
         Returns:
             A dictionary mapping request IDs to their corresponding WorkflowEvent (type='request_info').
         """
-        ...
+        pass
 
 
 class InProcRunnerContext:

python/packages/orchestrations/agent_framework_orchestrations/_magentic.py

@@ -474,22 +474,22 @@ def __init__(
     @abstractmethod
     async def plan(self, magentic_context: MagenticContext) -> Message:
         """Create a plan for the task."""
-        ...
+        raise NotImplementedError
 
     @abstractmethod
     async def replan(self, magentic_context: MagenticContext) -> Message:
         """Replan for the task."""
-        ...
+        raise NotImplementedError
 
     @abstractmethod
     async def create_progress_ledger(self, magentic_context: MagenticContext) -> MagenticProgressLedger:
         """Create a progress ledger."""
-        ...
+        raise NotImplementedError
 
     @abstractmethod
     async def prepare_final_answer(self, magentic_context: MagenticContext) -> Message:
         """Prepare the final answer."""
-        ...
+        raise NotImplementedError
 
     def on_checkpoint_save(self) -> dict[str, Any]:
         """Serialize runtime state for checkpointing."""