enterprise-kb-rag/2.2_LangChain基础知识/10_chain_simple.py

from pathlib import Path
import sys

sys.path.append(str(Path(__file__).resolve().parents[1]))

from _chapter2_config import as_text, get_chat_model, print_dependency_hint


try:
    from langchain_core.prompts import PromptTemplate
except ModuleNotFoundError as exc:
    print_dependency_hint(exc)
    raise SystemExit(1)


def main() -> None:
    template = "我的邻居姓{lastname}，他生了个儿子，给他儿子起个名字"
    prompt = PromptTemplate(input_variables=["lastname"], template=template)

    try:
        llm = get_chat_model(temperature=0)
    except ModuleNotFoundError as exc:
        print_dependency_hint(exc)
        raise SystemExit(1)

    chain = prompt | llm
    result = chain.invoke({"lastname": "王"})
    print(as_text(result))


if __name__ == "__main__":
    main()