Adding memory

Обновлено 24 мая 2024

This shows how to add memory to an arbitrary chain. Right now, you can use the memory classes but need to hook it up manually

%pip install --upgrade --quiet  langchain langchain-openai

from operator import itemgetter

from langchain.memory import ConversationBufferMemory
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_core.runnables import RunnableLambda, RunnablePassthrough
from langchain_openai import ChatOpenAI

model = ChatOpenAI()
prompt = ChatPromptTemplate.from_messages(
    [
        ("system", "You are a helpful chatbot"),
        MessagesPlaceholder(variable_name="history"),
        ("human", "{input}"),
    ]
)

memory = ConversationBufferMemory(return_messages=True)

memory.load_memory_variables({})

    {'history': []}

chain = (
    RunnablePassthrough.assign(
        history=RunnableLambda(memory.load_memory_variables) | itemgetter("history")
    )
    | prompt
    | model
)

inputs = {"input": "hi im bob"}
response = chain.invoke(inputs)
response

    AIMessage(content='Hello Bob! How can I assist you today?', additional_kwargs={}, example=False)

memory.save_context(inputs, {"output": response.content})

memory.load_memory_variables({})

    {'history': [HumanMessage(content='hi im bob', additional_kwargs={}, example=False),
  AIMessage(content='Hello Bob! How can I assist you today?', additional_kwargs={}, example=False)]}

inputs = {"input": "whats my name"}
response = chain.invoke(inputs)
response

    AIMessage(content='Your name is Bob.', additional_kwargs={}, example=False)