Could not parse LLM output:

[williamharris0214]

llm = ChatOpenAI(model_name="gpt-3.5-turbo",temperature=0.3)
memory = ConversationBufferMemory(memory_key="chat_history",return_messages=True)
agent_chain = initialize_agent(tools, llm, agent=AgentType.CHAT_CONVERSATIONAL_REACT_DESCRIPTION, verbose=True, memory=memory)

human_message = "hi"

while(True):
  bot_message = agent_chain.run(input=human_message);
  print(">>>>> Assist: ", bot_message)
  print(">>>>> Human:", end=" ")
  human_message = input();

Traceback (most recent call last):
File "D:\work\gpt\booking_bot\app.py", line 48, in
bot_message = agent_chain.run(input=human_message);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\chains\base.py", line 492, in run
return self(kwargs, callbacks=callbacks, tags=tags, metadata=metadata)[
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\chains\base.py", line 292, in call
raise e
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\chains\base.py", line 286, in call
self._call(inputs, run_manager=run_manager)
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\agents\agent.py", line 1122, in _call
next_step_output = self._take_next_step(
^^^^^^^^^^^^^^^^^^^^^
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\agents\agent.py", line 930, in _take_next_step
raise e
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\agents\agent.py", line 919, in _take_next_step
output = self.agent.plan(
^^^^^^^^^^^^^^^^
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\agents\agent.py", line 532, in plan
return self.output_parser.parse(full_output)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\work\gpt\booking_bot\env\Lib\site-packages\langchain\agents\conversational_chat\output_parser.py", line 50, in parse
raise OutputParserException(f"Could not parse LLM output: {text}") from e
langchain.schema.output_parser.OutputParserException: Could not parse LLM output: Hello! How can I assist you today?

what's wrong with this?

[dosubot[bot]]

🤖

The error you're encountering, OutputParserException: Could not parse LLM output, is raised by the parse method in the ChatOutputParser class in LangChain. This method attempts to parse the output of the language model using a regex pattern and JSON parsing. If the output does not match the pattern or cannot be parsed into JSON, it raises an OutputParserException.

The expected format of the output from the language model that the parse method can successfully parse is a JSON string enclosed in triple backticks. The JSON string should contain an "action" key. Optionally, it can also contain an "action_input" key. Here's an example of the expected format:

{
"action": "some_action",
"action_input": {
"some_key": "some_value"
}
}

If the output of the language model is not in this expected format, or if it includes both a final answer and a parse-able action, the parse method of ChatOutputParser will not be able to parse the output correctly, leading to the OutputParserException.

In your case, the error message indicates that the output from the language model was "Hello! How can I assist you today?". This output does not match the expected format, hence the error.

You can try to debug this issue by checking the output of the language model. Make sure it's in the expected format and does not include both a final answer and a parse-able action.

I hope this helps! If you have any other questions, feel free to ask.

Sources

• ValueError: Could not parse LLM output:
• Bug : could not parse LLM output: {llm_output}") when I run the same question several times
• ValueError: Could not parse LLM output:
• libs/langchain/langchain/output_parsers/retry.py
• libs/langchain/langchain/output_parsers/list.py
• libs/langchain/langchain/schema/output_parser.py
• libs/langchain/langchain/output_parsers/init.py
• libs/langchain/langchain/agents/chat/output_parser.py

---

This response is meant to be useful and save you time. It is not meant to be a precise solution, but rather a starting point for your own research.

Help me be more useful! Please leave a 👍 if this is helpful and 👎 if it is irrelevant.

If you want to continue the conversation, start your reply with @dosu-bot.

[dosubot[bot]]

🤖

Based on the traceback you've provided, it seems like the error is being raised by the parse method in the ChatOutputParser class. This method is trying to parse the output of the language model using a regex pattern and JSON parsing. If the output does not match the pattern or cannot be parsed into JSON, it raises an OutputParserException.

The expected format of the output from the language model that the parse method in the ChatOutputParser class can successfully parse is a string that includes a JSON object enclosed in triple backticks (```). The JSON object should contain an "action" key, and it may optionally contain an "action_input" key.

Here is the relevant code:

def parse(self, text: str) -> Union[AgentAction, AgentFinish]:
    includes_answer = FINAL_ANSWER_ACTION in text
    try:
        found = self.pattern.search(text)
        if not found:
            # Fast fail to parse Final Answer.
            raise ValueError("action not found")
        action = found.group(1)
        response = json.loads(action.strip())
        includes_action = "action" in response
        if includes_answer and includes_action:
            raise OutputParserException(
                "Parsing LLM output produced a final answer "
                f"and a parse-able action: {text}"
            )
        return AgentAction(
            response["action"], response.get("action_input", {}), text
        )

    except Exception:
        if not includes_answer:
            raise OutputParserException(f"Could not parse LLM output: {text}")
        output = text.split(FINAL_ANSWER_ACTION)[-1].strip()
        return AgentFinish({"output": output}, text)

If the output of the language model is not in the expected format (matches the regex pattern and can be parsed into JSON), or if it includes both a final answer and a parse-able action, the parse method of ChatOutputParser will not be able to parse the output correctly, leading to the OutputParserException.

You can find more details in the LangChain repository, specifically in the ChatOutputParser class.

I hope this helps! If you have any other questions or need further clarification, feel free to ask.

Sources

• ValueError: Could not parse LLM output:
• Bug : could not parse LLM output: {llm_output}") when I run the same question several times
• ValueError: Could not parse LLM output:
• libs/langchain/langchain/output_parsers/retry.py
• libs/langchain/langchain/output_parsers/list.py
• libs/langchain/langchain/schema/output_parser.py
• libs/langchain/langchain/output_parsers/init.py
• libs/langchain/langchain/agents/chat/output_parser.py

---

This response is meant to be useful and save you time. It is not meant to be a precise solution, but rather a starting point for your own research.

Help me be more useful! Please leave a 👍 if this is helpful and 👎 if it is irrelevant.

If you want to continue the conversation, start your reply with @dosu-bot.