添加消息历史记录（内存）

from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_openai.chat_models import ChatOpenAI
 
model = ChatOpenAI()
prompt = ChatPromptTemplate.from_messages(
    [
        (
            "system",
            "You're an assistant who's good at {ability}. Respond in 20 words or fewer",
        ),
        MessagesPlaceholder(variable_name="history"),
        ("human", "{input}"),
    ]
)
runnable = prompt | model

from langchain_community.chat_message_histories import ChatMessageHistory
from langchain_core.chat_history import BaseChatMessageHistory
from langchain_core.runnables.history import RunnableWithMessageHistory
 
store = {}
 
 
def get_session_history(session_id: str) -> BaseChatMessageHistory:
    if session_id not in store:
        store[session_id] = ChatMessageHistory()
    return store[session_id]
 
 
with_message_history = RunnableWithMessageHistory(
    runnable,
    get_session_history,
    input_messages_key="input",
    history_messages_key="history",
)

with_message_history.invoke(
    {"ability": "math", "input": "What does cosine mean?"},
    config={"configurable": {"session_id": "abc123"}},
)

AIMessage(content='Cosine is a trigonometric function that calculates the ratio of the adjacent side to the hypotenuse of a right triangle.')

# 记住
with_message_history.invoke(
    {"ability": "math", "input": "What?"},
    config={"configurable": {"session_id": "abc123"}},
)

AIMessage(content='Cosine is a mathematical function used to calculate the length of a side in a right triangle.')

# 新的session_id --> 不会记住。
with_message_history.invoke(
    {"ability": "math", "input": "What?"},
    config={"configurable": {"session_id": "def234"}},
)

AIMessage(content='I can help with math problems. What do you need assistance with?')

from langchain_core.runnables import ConfigurableFieldSpec
 
store = {}
 
 
def get_session_history(user_id: str, conversation_id: str) -> BaseChatMessageHistory:
    if (user_id, conversation_id) not in store:
        store[(user_id, conversation_id)] = ChatMessageHistory()
    return store[(user_id, conversation_id)]
 
 
with_message_history = RunnableWithMessageHistory(
    runnable,
    get_session_history,
    input_messages_key="input",
    history_messages_key="history",
    history_factory_config=[
        ConfigurableFieldSpec(
            id="user_id",
            annotation=str,
            name="User ID",
            description="Unique identifier for the user.",
            default="",
            is_shared=True,
        ),
        ConfigurableFieldSpec(
            id="conversation_id",
            annotation=str,
            name="Conversation ID",
            description="Unique identifier for the conversation.",
            default="",
            is_shared=True,
        ),
    ],
)

with_message_history.invoke(
    {"ability": "math", "input": "Hello"},
    config={"configurable": {"user_id": "123", "conversation_id": "1"}},
)

from langchain_core.messages import HumanMessage
from langchain_core.runnables import RunnableParallel
 
chain = RunnableParallel({"output_message": ChatOpenAI()})
 
 
def get_session_history(session_id: str) -> BaseChatMessageHistory:
    if session_id not in store:
        store[session_id] = ChatMessageHistory()
    return store[session_id]
 
 
with_message_history = RunnableWithMessageHistory(
    chain,
    get_session_history,
    output_messages_key="output_message",
)
 
with_message_history.invoke(
    [HumanMessage(content="What did Simone de Beauvoir believe about free will")],
    config={"configurable": {"session_id": "baz"}},
)

{'output_message': AIMessage(content="Simone de Beauvoir believed in the existence of free will. She argued that individuals have the ability to make choices and determine their own actions, even in the face of social and cultural constraints. She rejected the idea that individuals are purely products of their environment or predetermined by biology or destiny. Instead, she emphasized the importance of personal responsibility and the need for individuals to actively engage in creating their own lives and defining their own existence. De Beauvoir believed that freedom and agency come from recognizing one's own freedom and actively exercising it in the pursuit of personal and collective liberation.")}

with_message_history.invoke(
    [HumanMessage(content="How did this compare to Sartre")],
    config={"configurable": {"session_id": "baz"}},
)

{'output_message': AIMessage(content='Simone de Beauvoir\'s views on free will were closely aligned with those of her contemporary and partner Jean-Paul Sartre. Both de Beauvoir and Sartre were existentialist philosophers who emphasized the importance of individual freedom and the rejection of determinism. They believed that human beings have the capacity to transcend their circumstances and create their own meaning and values.\n\nSartre, in his famous work "Being and Nothingness," argued that human beings are condemned to be free, meaning that we are burdened with the responsibility of making choices and defining ourselves in a world that lacks inherent meaning. Like de Beauvoir, Sartre believed that individuals have the ability to exercise their freedom and make choices in the face of external and internal constraints.\n\nWhile there may be some nuanced differences in their philosophical writings, overall, de Beauvoir and Sartre shared a similar belief in the existence of free will and the importance of individual agency in shaping one\'s own life.')}

RunnableWithMessageHistory(
    ChatOpenAI(),
    get_session_history,
)

from operator import itemgetter
 
RunnableWithMessageHistory(
    itemgetter("input_messages") | ChatOpenAI(),
    get_session_history,
    input_messages_key="input_messages",
)

%pip install --upgrade --quiet redis

docker run -d -p 6379:6379 -p 8001:8001 redis/redis-stack:latest

REDIS_URL = "redis://localhost:6379/0"

# os.environ["LANGCHAIN_TRACING_V2"] = "true"
# os.environ["LANGCHAIN_API_KEY"] = getpass.getpass()

from langchain_community.chat_message_histories import RedisChatMessageHistory
 
 
def get_message_history(session_id: str) -> RedisChatMessageHistory:
    return RedisChatMessageHistory(session_id, url=REDIS_URL)
 
 
with_message_history = RunnableWithMessageHistory(
    runnable,
    get_message_history,
    input_messages_key="input",
    history_messages_key="history",
)

with_message_history.invoke(
    {"ability": "math", "input": "What does cosine mean?"},
    config={"configurable": {"session_id": "foobar"}},
)

AIMessage(content='Cosine is a trigonometric function that represents the ratio of the adjacent side to the hypotenuse in a right triangle.')

with_message_history.invoke(
    {"ability": "math", "input": "What's its inverse"},
    config={"configurable": {"session_id": "foobar"}},
)

AIMessage(content='The inverse of cosine is the arccosine function, denoted as acos or cos^-1, which gives the angle corresponding to a given cosine value.')