From 95b77a52153b10091e480be0b5e7a366d3b3f796 Mon Sep 17 00:00:00 2001
From: Nir Gazit <nirga@users.noreply.github.com>
Date: Tue, 20 Jun 2023 08:03:58 +0300
Subject: [PATCH] Fix Custom LLM Agent example (#6429)

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The `CustomOutputParser` needs to throw `OutputParserException` when it
fails to parse the response from the agent, so that the executor can
[catch it and
retry](https://github.com/hwchase17/langchain/blob/be9371ca8f363bf1c748ac4af7fb4a0d75a365c5/langchain/agents/agent.py#L767)
when `handle_parsing_errors=True`.

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#### Who can review?

Tag maintainers/contributors who might be interested: @hwchase17

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---
 docs/snippets/modules/agents/how_to/custom_llm_agent.mdx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/snippets/modules/agents/how_to/custom_llm_agent.mdx b/docs/snippets/modules/agents/how_to/custom_llm_agent.mdx
index ac892816..eebf7429 100644
--- a/docs/snippets/modules/agents/how_to/custom_llm_agent.mdx
+++ b/docs/snippets/modules/agents/how_to/custom_llm_agent.mdx
@@ -22,7 +22,7 @@ from langchain.agents import Tool, AgentExecutor, LLMSingleActionAgent, AgentOut
 from langchain.prompts import StringPromptTemplate
 from langchain import OpenAI, SerpAPIWrapper, LLMChain
 from typing import List, Union
-from langchain.schema import AgentAction, AgentFinish
+from langchain.schema import AgentAction, AgentFinish, OutputParserException
 import re
 ```
 
@@ -135,7 +135,7 @@ class CustomOutputParser(AgentOutputParser):
         regex = r"Action\s*\d*\s*:(.*?)\nAction\s*\d*\s*Input\s*\d*\s*:[\s]*(.*)"
         match = re.search(regex, llm_output, re.DOTALL)
         if not match:
-            raise ValueError(f"Could not parse LLM output: `{llm_output}`")
+            raise OutputParserException(f"Could not parse LLM output: `{llm_output}`")
         action = match.group(1).strip()
         action_input = match.group(2)
         # Return the action and action input