LangChain

LangChain#

LangChain is a framework for developing applications powered by large language models (LLMs).

Architecture#

https://python.langchain.com/svg/langchain_stack_112024.svg

  • langchain-core: 基础抽象和LangChain表达式 (LCEL)

  • Integration packages (e.g. langchain-openai, langchain-anthropic, etc.): Important integrations have been split into lightweight packages that are co-maintained by the LangChain team and the integration developers.

  • langchain: 组成应用程序认知架构的链、代理和检索策略

  • langchain-community: 第三方集成

  • LangGraph: 通过将步骤建模为图中的边和节点，构建强大且有状态的多参与者应用程序

  • LangServe: 将LangChain链部署为REST API

  • LangSmith: 一个开发者平台，让您调试、测试、评估和监控LLM应用程序

OllamaLLM#

Installation#

pip install -U langchain-ollama

Usage#

from langchain_core.prompts import ChatPromptTemplate
from langchain_ollama.llms import OllamaLLM
template = """Question: {question}
Answer: Let's think step by step."""
prompt = ChatPromptTemplate.from_template(template)
model = OllamaLLM(model="llama3.1")
chain = prompt | model
chain.invoke({"question": "What is LangChain?"})

References#

Contents