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## Description In `langchain_prompty`, messages are templated by Prompty. However, a call to `ChatPromptTemplate` was initiating a second templating. We now convert parsed messages to `Message` objects before calling `ChatPromptTemplate`, signifying clearly that they are already templated. We also revert #25739 , which applied to this second templating, which we now avoid, and did not fix the original issue. ## Issue Closes #25703
36 lines
1.2 KiB
Python
36 lines
1.2 KiB
Python
from typing import Any, Dict
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from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
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from langchain_core.runnables import Runnable, RunnableLambda
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from .parsers import RoleMap
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from .utils import load, prepare
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def create_chat_prompt(
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path: str,
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input_name_agent_scratchpad: str = "agent_scratchpad",
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) -> Runnable[Dict[str, Any], ChatPromptTemplate]:
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"""Create a chat prompt from a Langchain schema."""
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def runnable_chat_lambda(inputs: Dict[str, Any]) -> ChatPromptTemplate:
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p = load(path)
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parsed = prepare(p, inputs)
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# Parsed messages have been templated
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# Convert to Message objects to avoid templating attempts in ChatPromptTemplate
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lc_messages = []
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for message in parsed:
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message_class = RoleMap.get_message_class(message["role"])
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lc_messages.append(message_class(content=message["content"]))
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lc_messages.append(
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MessagesPlaceholder(
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variable_name=input_name_agent_scratchpad, optional=True
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) # type: ignore[arg-type]
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)
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lc_p = ChatPromptTemplate.from_messages(lc_messages)
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lc_p = lc_p.partial(**p.inputs)
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return lc_p
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return RunnableLambda(runnable_chat_lambda)
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