@RobertCraigie Sorry, there are still some issue

[CharlieChiu5]

          @RobertCraigie Sorry, there are still some issue

client = OpenAI()

class EventHandler(AssistantEventHandler):
    def __init__(self) -> None:
        super().__init__()

    @override
    def on_event(self, event: AssistantStreamEvent) -> None:
        if isinstance(event, ThreadRunStepCompleted):
            if event.data.type == 'tool_calls':
                for tool_call in event.data.step_details.tool_calls:
                    # type(tool_call) is <class 'dict'>
                    if tool_call.type == 'code_interpreter':
                        pass
                    elif tool_call.type == 'file_search':
                        pass

    @override
    def _emit_sse_event(self, event: AssistantStreamEvent) -> None:
        if event.event == "thread.run.step.delta":
            print(f'{type(event)} {type(event.data)} {type(event.data.delta)} {str(event.data.delta)}')
        super()._emit_sse_event(event)


client = OpenAI()

assistant = client.beta.assistants.create(
    name="Math Tutor",
    instructions="You are a personal math tutor. Write and run code to answer math questions.",
    tools=[{"type": "code_interpreter"}],
    model="gpt-4o-mini",
)

with client.beta.threads.create_and_run_stream(
    assistant_id=assistant.id,
    model="gpt-4o-mini",
    instructions="Use browser tool first to answer the user's question",
    thread={"messages": [{"role": "user", "content": "Who is Tom"}]},
    tool_choice="required",
    event_handler=EventHandler()
) as stream:
    stream.until_done()

Output:

<class 'openai.types.beta.assistant_stream_event.ThreadRunStepDelta'> <class 'openai.types.beta.threads.runs.run_step_delta_event.RunStepDeltaEvent'> <class 'openai.types.beta.threads.runs.run_step_delta.RunStepDelta'> 
RunStepDelta(step_details=ToolCallDeltaObject(type='tool_calls', tool_calls=[CodeInterpreterToolCallDelta(index=0, type='browser', id='call_6GeU3til5JdXMxUCRmjLZK0L', code_interpreter=None, browser={})]))
/lib/python3.12/site-packages/pydantic/main.py:308: UserWarning: Pydantic serializer warnings:
  Expected `Union[RunStepDeltaMessageDelta, ToolCallDeltaObject]` but got `ToolCallDeltaObject` - serialized value may not be as expected
  Expected `Union[CodeInterpreterToolCallDelta, FileSearchToolCallDelta, FunctionToolCallDelta]` but got `CodeInterpreterToolCallDelta` - serialized value may not be as expected
  return self.__pydantic_serializer__.to_python(
Traceback (most recent call last):
  File "demo.py", line 51, in <module>
    stream.until_done()
  File "/lib/python3.12/site-packages/openai/lib/streaming/_assistants.py", line 102, in until_done
    consume_sync_iterator(self)
  File "/lib/python3.12/site-packages/openai/_utils/_streams.py", line 6, in consume_sync_iterator
    for _ in iterator:
  File "/lib/python3.12/site-packages/openai/lib/streaming/_assistants.py", line 69, in __iter__
    for item in self._iterator:
  File "/lib/python3.12/site-packages/openai/lib/streaming/_assistants.py", line 406, in __stream__
    self._emit_sse_event(event)
  File "demo.py", line 31, in _emit_sse_event
    super()._emit_sse_event(event)
  File "/lib/python3.12/site-packages/openai/lib/streaming/_assistants.py", line 256, in _emit_sse_event
    self.on_event(event)
  File "demo.py", line 22, in on_event
    if tool_call.type == 'code_interpreter':
       ^^^^^^^^^^^^^^
AttributeError: 'dict' object has no attribute 'type'

New environment:

> python -m pip list | grep -E 'openai|pydantic'              
openai                        1.36.0
pydantic                      2.8.2
pydantic_core                 2.20.1

> python --version
Python 3.12.2

> uname -a
Darwin Kernel Version 23.3.0

Originally posted by @kunerzzz in #1574 (comment)