FastAPI+vue3+ollama+Langchain大模型开发实战教程

安装ollama

下载：https://ollama.com/download/OllamaSetup.exe

下载以后双击安装。

启动模型

参考文档：
https://ollama.fan/getting-started/#model-library
https://ollama.com/library
https://ollama.com/library/qwen2

启动模型：

ollama run qwen2:0.5b

聊天对话

参考文档：
https://ollama.fan/getting-started/examples/001-python-simplechat/

创建虚拟环境：

conda create --name langchain python=3.12

main.py

import json
import requests

model = "qwen2:0.5b" 

def chat(messages):
    r = requests.post(
        "http://127.0.0.1:11434/api/chat",
        json={"model": model, "messages": messages, "stream": True},
    )
    r.raise_for_status()
    output = ""


    for line in r.iter_lines():
        body = json.loads(line)
        if "error" in body:
            raise Exception(body["error"])
        if body.get("done") is False:
            message = body.get("message", "")
            content = message.get("content", "")
            output += content
            # the response streams one token at a time, print that as we receive it
            print(content, end="", flush=True)

        if body.get("done", False):
            message["content"] = output
            return message


def main():
    messages = []
    while True:
        user_input = input("Enter a prompt: ")
        if not user_input:
            exit()
        print()
        messages.append({"role": "user", "content": user_input})
        message = chat(messages)
        messages.append(message)
        print("\n\n")


if __name__ == "__main__":

    main()