[BUG] The content of assistant is <promptflow.tracing._trace.TracedIterator object at 0x………>, which causes the chat_history passed to LLM to be wrong

[21-10-4]

Describe the bug A clear and concise description of the bug. 通过 pf flow test --flow new-chat-flow-created-at-2024-10-11 --interactive在终端进行交互式问答。 问答中，发现AI好像没有上下记忆，经过trace发现assistant 部分的content都是 <promptflow.tracing._trace.TracedIterator object at 0x………>，只有assistant的最后一次回答的content是正确的

How To Reproduce the bug Steps to reproduce the behavior, how frequent can you experience the bug:

1. create new flow->chat flow with a template

Expected behavior A clear and concise description of what you expected to happen.

Screenshots If applicable, add screenshots to help explain your problem.

Running Information(please complete the following information):

• Promptflow Package Version using pf -v: [e.g. 0.0.102309906]
• Operating System: [e.g. Ubuntu 20.04, Windows 11]
• Python Version using python --version: [e.g. python==3.10.12]

  
  {
  "promptflow": "1.16.1",
  "promptflow-core": "1.16.1",
  "promptflow-devkit": "1.16.1",
  "promptflow-tracing": "1.16.1"
  }

Executable '/home/xxx/anaconda3/envs/reflextion/bin/python' Python (Linux) 3.8.19 (default, Mar 20 2024, 19:58:24) [GCC 11.2.0]

**Additional context**
Add any other context about the problem here.

[dburik]

I'm experiencing the same issue with Prompt flow 1.16.1. Using the following code as a workaround:

from promptflow.tracing.contracts.iterator_proxy import IteratorProxy

if isinstance(output, IteratorProxy):
    output= "".join(output.items)

Can someone from Prompt flow team provide a comment on this? Is this a bug or an intended but undocumented change in the API?