3. 函数调用

# 3.1 核心概念

Function Calling 是 OpenAI Assistants API 提供的一项功能（现在绝大多数模型都已经支持），允许开发者预先定义一组可供 AI 助手调用的函数。这些函数被描述为结构化的工具，包含名称、用途说明以及 JSON 格式的参数定义。其主要目的是使助手能够在对话过程中，当遇到需要执行特定操作（如查询外部数据、执行实际操作、调用系统接口等）的场景时，不再仅仅依靠纯文本生成回答，而是能够触发这些预定义函数，从而获得精确且结构化的输出。

# 3.2 加减乘除案例

# 3.2.1 自定义函数

def add(num1, num2):
    return num1 + num2

def sub(num1, num2):
    return num1 - num2

def mul(num1, num2):
    return num1 * num2

def div(num1, num2):
    return num1 / num2 if num2 != 0 else "除数不能为0"

function_map = {
    "add": add,
    "sub": sub,
    "mul": mul,
    "div": div
}

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# 3.2.2 创建助手

from openai import OpenAI
import time
import json

client = OpenAI()

assistant = client.beta.assistants.create(
    name="计算器",
    instructions="你是一个计算器，请根据用户的问题结合我定义的函数给出回答",
    model="gpt-4o",
    tools=[
        {
            "type": "function",
            "function": {
                "name": "add",
                "description": "计算两个数的和",
                "parameters": {
                    "type": "object",
                    "properties": {
                        "num1": {
                            "type": "number",
                            "description": "第一个数"
                        },
                        "num2": {
                            "type": "number",
                            "description": "第二个数"
                        }
                    },
                    "required": ["num1", "num2"]
                }
            }
        },
        {
            "type": "function",
            "function": {
                "name": "sub",
                "description": "计算两个数的差",
                "parameters": {
                    "type": "object",
                    "properties": {
                        "num1": {
                            "type": "number",
                            "description": "第一个数"
                        },
                        "num2": {
                            "type": "number",
                            "description": "第二个数"
                        }
                    },
                    "required": ["num1", "num2"]
                }
            }
        },
        {
            "type": "function",
            "function": {
                "name": "mul",
                "description": "计算两个数的乘积",
                "parameters": {
                    "type": "object",
                    "properties": {
                        "num1": {
                            "type": "number",
                            "description": "第一个数"
                        },
                        "num2": {
                            "type": "number",
                            "description": "第二个数"
                        }
                    },
                    "required": ["num1", "num2"]
                }
            }
        },
        {
            "type": "function",
            "function": {
                "name": "div",
                "description": "计算两个数的商",
                "parameters": {
                    "type": "object",
                    "properties": {
                        "num1": {
                            "type": "number",
                            "description": "第一个数"
                        },
                        "num2": {
                            "type": "number",
                            "description": "第二个数"
                        }
                    },
                    "required": ["num1", "num2"]
                }
            }
        }
    ]
)

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# 3.2.3 创建会话并等待响应

thread = client.beta.threads.create()
message = client.beta.threads.messages.create(
    thread_id=thread.id,
    role="user",
    content="请根据我的要求按照优先级规则逐步调用函数。3 + 5 * (8 - 2) / 2 等于多少？",
)
print(f"------------------prompt------------------")
print(message.content[0].text.value)

run = client.beta.threads.runs.create_and_poll(
    thread_id=thread.id,
    assistant_id=assistant.id,
)

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# 3.2.4 循环处理function_call直至完成

i = 1
while True:
    if run.status == 'requires_action':
        tool_outputs = []
        print(f"------------------第{i}次请求回调tools------------------")
        i = i + 1
        for tool in run.required_action.submit_tool_outputs.tool_calls:
            function_call = function_map.get(tool.function.name)
            if function_call:
                args = json.loads(tool.function.arguments)
                print(f"调用函数{tool.function.name}，参数为{args}")
                result = function_call(
                    num1=float(args["num1"]),
                    num2=float(args["num2"])
                )
                tool_outputs.append({
                    "tool_call_id": tool.id,
                    "output": str(result)
                })

        if tool_outputs:
            try:
                run = client.beta.threads.runs.submit_tool_outputs(
                    thread_id=thread.id,
                    run_id=run.id,
                    tool_outputs=tool_outputs
                )
            except Exception as e:
                print("Failed to submit tool outputs:", e)
                break

    # 检查运行状态
    run = client.beta.threads.runs.retrieve(
        thread_id=thread.id,
        run_id=run.id
    )

    if run.status == 'completed':
        messages = client.beta.threads.messages.list(
            thread_id=thread.id
        )
        print(f"------------------最终回答------------------")
        print(messages.data[0].content[0].text.value)
        break
    elif run.status == 'failed':
        print("Run failed")
        break

    time.sleep(1)

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编辑

#Function Calling

上次更新: 2025/09/18, 08:16:15

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