一文彻底搞懂智能体Agent基于Function Calling的工具调用

​​ #!/bin/bash export OPENAI_API_BASE="https://dashscope.aliyuncs.com/compatible-mode/v1" export OPENAI_API_KEY="sk-xxx"# 替换为你的key curl ${OPENAI_API_BASE}/chat/completions \ -H"Content-Type: application/json" \ -H"Authorization: Bearer $OPENAI_API_KEY" \ -d'{ "model": "qwen-plus", "messages": [ { "role": "user", "content": "北京和广州天气怎么样" } ], "tools": [ { "type": "function", "function": { "name": "get_weather", "description": "Get weather", "parameters": { "type": "object", "properties": { "location": { "type": "string", "description": "location" } }, "required": ["location"] } } } ], "tool_choice": "auto" }' 

​ { "choices": [ { "message": { "content": "", "role": "assistant", "tool_calls": [ { "index": 0, "id": "call_3ee91e7e0e0b420d", "type": "function", "function": { "name": "get_weather", "arguments": "{\"location\": \"北京\"}" } } ] }, "finish_reason": "tool_calls", "index": 0, "logprobs": null } ], "object": "chat.completion", "usage": { "prompt_tokens": 166, "completion_tokens": 17, "total_tokens": 183, "prompt_tokens_details": { "cached_tokens": 0 } }, "created": , "system_fingerprint": null, "model": "qwen-plus", "id": "chatcmpl-7c4fc4c8-92fa-90cc-aaf6-f673d7ab4220"} 

​ { "msg": "success", "code": 0, "data": { "location": { "id": "54511", "name": "北京", "path": "中国, 北京, 北京" }, "now": { "precipitation": 0.0, "temperature": 24.3, "pressure": 1007.0, "humidity": 35.0, "windDirection": "西南风", "windDirectionDegree": 207.0, "windSpeed": 2.7, "windScale": "微风" }, "alarm": [], "lastUpdate": "2025/04/20 14:25" }} 

​ #!/bin/bash export OPENAI_API_BASE="https://dashscope.aliyuncs.com/compatible-mode/v1" export OPENAI_API_KEY="sk-xxx"# 替换为你的key curl ${OPENAI_API_BASE}/chat/completions \ -H"Content-Type: application/json" \ -H"Authorization: Bearer $OPENAI_API_KEY" \ -d'{ "model": "qwen-plus", "messages": [ { "role": "user", "content": "北京和广州天气怎么样" }, { "role": "assistant", "tool_calls": [ { "id": "call_3ee91e7e0e0b420d", "type": "function", "function": { "name": "get_weather", "arguments": "{\"location\": \"北京\"}" } } ] }, { "role": "tool", "content": "{\"msg\":\"success\",\"code\":0,\"data\":{\"location\":{\"id\":\"54511\",\"name\":\"北京\",\"path\":\"中国, 北京, 北京\"},\"now\":{\"precipitation\":0.0,\"temperature\":24.3,\"pressure\":1007.0,\"humidity\":35.0,\"windDirection\":\"西南风\",\"windDirectionDegree\":207.0,\"windSpeed\":2.7,\"windScale\":\"微风\"},\"alarm\":[],\"lastUpdate\":\"2025/04/20 14:25\"}}", "tool_call_id": "call_3ee91e7e0e0b420d" } ], "tools": [ { "type": "function", "function": { "name": "get_weather", "description": "Get weather", "parameters": { "type": "object", "properties": { "location": { "type": "string", "description": "location" } }, "required": [ "location" ] } } } ], "tool_choice": "auto" }' 

​ { "choices": [ { "message": { "content": "", "role": "assistant", "tool_calls": [ { "index": 0, "id": "call_4a920a1bb9d54f8894c1ac", "type": "function", "function": { "name": "get_weather", "arguments": "{\"location\": \"广州\"}" } } ] }, "finish_reason": "tool_calls", "index": 0, "logprobs": null } ], "object": "chat.completion", "usage": { "prompt_tokens": 312, "completion_tokens": 19, "total_tokens": 331, "prompt_tokens_details": { "cached_tokens": 0 } }, "created": , "system_fingerprint": null, "model": "qwen-plus", "id": "chatcmpl-5e002b5b-7220-927e-9637-f80658"} 

​ { "msg": "success", "code": 0, "data": { "location": { "id": "59287", "name": "广州", "path": "中国, 广东, 广州" }, "now": { "precipitation": 0.0, "temperature": 30.1, "pressure": 1002.0, "humidity": 64.0, "windDirection": "东南风", "windDirectionDegree": 167.0, "windSpeed": 2.4, "windScale": "微风" }, "alarm": [], "lastUpdate": "2025/04/20 14:25" }} 

​ #!/bin/bash export OPENAI_API_BASE="https://dashscope.aliyuncs.com/compatible-mode/v1" export OPENAI_API_KEY="sk-xxx"# 替换为你的key curl ${OPENAI_API_BASE}/chat/completions \ -H"Content-Type: application/json" \ -H"Authorization: Bearer $OPENAI_API_KEY" \ -d'{ "model": "qwen-plus", "messages": [ { "role": "user", "content": "北京和广州天气怎么样" }, { "role": "assistant", "tool_calls": [ { "id": "call_3ee91e7e0e0b420d", "type": "function", "function": { "name": "get_weather", "arguments": "{\"location\": \"北京\"}" } } ] }, { "role": "tool", "content": "{\"msg\":\"success\",\"code\":0,\"data\":{\"location\":{\"id\":\"54511\",\"name\":\"北京\",\"path\":\"中国, 北京, 北京\"},\"now\":{\"precipitation\":0.0,\"temperature\":24.3,\"pressure\":1007.0,\"humidity\":35.0,\"windDirection\":\"西南风\",\"windDirectionDegree\":207.0,\"windSpeed\":2.7,\"windScale\":\"微风\"},\"alarm\":[],\"lastUpdate\":\"2025/04/20 14:25\"}}", "tool_call_id": "call_3ee91e7e0e0b420d" }, { "role": "assistant", "tool_calls": [ { "id": "call_4a920a1bb9d54f8894c1ac", "type": "function", "function": { "name": "get_weather", "arguments": "{\"location\": \"广州\"}" } } ] }, { "role": "tool", "content": "{\"msg\":\"success\",\"code\":0,\"data\":{\"location\":{\"id\":\"59287\",\"name\":\"广州\",\"path\":\"中国, 广东, 广州\"},\"now\":{\"precipitation\":0.0,\"temperature\":30.1,\"pressure\":1002.0,\"humidity\":64.0,\"windDirection\":\"东南风\",\"windDirectionDegree\":167.0,\"windSpeed\":2.4,\"windScale\":\"微风\"},\"alarm\":[],\"lastUpdate\":\"2025/04/20 14:25\"}}", "tool_call_id": "call_4a920a1bb9d54f8894c1ac" } ], "tools": [ { "type": "function", "function": { "name": "get_weather", "description": "Get weather", "parameters": { "type": "object", "properties": { "location": { "type": "string", "description": "location" } }, "required": [ "location" ] } } } ], "tool_choice": "auto" }' 

​ 北京的当前天气状况如下： - 温度：24.3℃ - 湿度：35% - 风向：西南风 - 风速：微风 广州的当前天气状况如下： - 温度：30.1℃ - 湿度：64% - 风向：东南风 - 风速：微风 以上信息均来自最近更新，希望对你有帮助！ 

​ { "choices": [ { "message": { "content": "北京的当前天气状况如下：\n- 温度：24.3℃\n- 湿度：35%\n- 风向：西南风\n- 风速：微风\n\n广州的当前天气状况如下：\n- 温度：30.1℃\n- 湿度：64%\n- 风向：东南风\n- 风速：微风 \n\n以上信息均来自最近更新，希望对你有帮助！", "role": "assistant" }, "finish_reason": "stop", "index": 0, "logprobs": null } ], "object": "chat.completion", "usage": { "prompt_tokens": 460, "completion_tokens": 105, "total_tokens": 565, "prompt_tokens_details": { "cached_tokens": 0 } }, "created": , "system_fingerprint": null, "model": "qwen-plus", "id": "chatcmpl-fd1edc89-3ddb-9e27-9029-d2be2c81f3c1"} 

​ uv init agent cd agent uv venv .venv\Scripts\activate uv add openai requests python-dotenv 

​ OPENAI_API_KEY=your_api_key_here OPENAI_BASE_URL=https://dashscope.aliyuncs.com/compatible-mode/v1 

​ maxIter = 5 # 最大迭代次数for iterSeq in range(1, maxIter+1): 构造chat completion请求(带tools列表和tool_choice) 迭代次数达到最大值，tool_choice设置为none(不再调用工具) 否则tool_choice设置为auto(根据需要调用工具) 获取chat completion结果 如果chat completion结果带有tool_calls 解析并调用相应函数 添加消息到消息列表，继续迭代 否则，表明无需调用工具，迭代结束，输出结果 

​ import jsonimport osimport requestsimport urllib.parsefrom typing import Iterablefrom openai import OpenAIfrom openai.types.chat.chat_completion_message_param import ChatCompletionMessageParamfrom openai.types.chat.chat_completion_message_tool_call import ( ChatCompletionMessageToolCall,)from openai.types.chat.chat_completion_user_message_param import ( ChatCompletionUserMessageParam,)from openai.types.chat.chat_completion_tool_message_param import ( ChatCompletionToolMessageParam,)from openai.types.chat.chat_completion_assistant_message_param import ( ChatCompletionAssistantMessageParam,) # 加载环境变量from dotenv import load_dotenvload_dotenv() api_key = os.getenv("OPENAI_API_KEY")base_url = os.getenv("OPENAI_API_BASE")model = "qwen-plus"client = OpenAI(api_key=api_key, base_url=base_url) # 工具定义tools = [ { "type": "function", "function": { "name": "get_weather", "description": "Get weather", "parameters": { "type": "object", "properties": { "location": {"type": "string", "description": "location"} }, "required": ["location"], }, }, }] # 实现获取天气def get_weather(location: str) -> str: url = "http://weather.cma.cn/api/autocomplete?q=" + urllib.parse.quote(location) response = requests.get(url) data = response.json() if data["code"] != 0: return "没找到该位置的信息" location_code = "" for item in data["data"]: str_array = item.split("|") if ( str_array[1] == location or str_array[1] + "市" == location or str_array[2] == location ): location_code = str_array[0] break if location_code == "": return "没找到该位置的信息" url = f"http://weather.cma.cn/api/now/{location_code}" return requests.get(url).text # 实现工具调用def invoke_tool( tool_call: ChatCompletionMessageToolCall,) -> ChatCompletionToolMessageParam: result = ChatCompletionToolMessageParam(role="tool", tool_call_id=tool_call.id) if tool_call.function.name == "get_weather": args = json.loads(tool_call.function.arguments) result["content"] = get_weather(args["location"]) else: result["content"] = "函数未定义" return result def main(): query = "北京和广州天气怎么样" messages: Iterable[ChatCompletionMessageParam] = list() messages.append(ChatCompletionUserMessageParam(role="user", cnotallow=query)) maxIter = 5 # 最大迭代次数 for iterSeq in range(1, maxIter+1): print(f">> iterSeq:{iterSeq}") print(f">>> messages: {messages}") # 当迭代次数达到最大值，不再调用工具 toolChoice = "auto" if iterSeq < maxIter else "none" # 向LLM发起请求 chat_completion = client.chat.completions.create( messages=messages, model=model, tools=tools, tool_choice=toolChoice ) tool_calls = chat_completion.choices[0].message.tool_calls content = chat_completion.choices[0].message.content if isinstance(tool_calls, list): # LLM的响应信息有tool_calls信息 messages.append( ChatCompletionAssistantMessageParam( role="assistant", tool_calls=tool_calls, cnotallow="" ) ) for tool_call in tool_calls: print(f">>> tool_call: {tool_call}") result = invoke_tool(tool_call) print(f">>> tool_call result: {result}") messages.append(result) else: # LLM的响应信息没有tool_calls信息，迭代结束，获取响应文本 print(f">>> final result: \n{content}") returnmain() 

​ >> iterSeq:1 >>> messages: [{'role': 'user', 'content': '北京和广州天气怎么样'}] >>> tool_call: ChatCompletionMessageToolCall(id='call_dbad99d', functinotallow=Function(arguments='{"location": "北京"}', name='get_weather'), type='function', index=0) >>> tool_call result: {'role': 'tool', 'tool_call_id': 'call_dbad99d', 'content': '{"msg":"success","code":0,"data":{"location":{"id":"54511","name":"北京","path":"中国, 北京, 北京"},"now":{"precipitation":0.0,"temperature":24.5,"pressure":1006.0,"humidity":34.0,"windDirection":"西南风","windDirectionDegree":191.0,"windSpeed":2.8,"windScale":"微风"},"alarm":[],"lastUpdate":"2025/04/20 15:35"}}'} >> iterSeq:2 >>> messages: [{'role': 'user', 'content': '北京和广州天气怎么样'}, {'role': 'assistant', 'tool_calls': [ChatCompletionMessageToolCall(id='call_dbad99d', functinotallow=Function(arguments='{"location": "北京"}', name='get_weather'), type='function', index=0)], 'content': ''}, {'role': 'tool', 'tool_call_id': 'call_dbad99d', 'content': '{"msg":"success","code":0,"data":{"location":{"id":"54511","name":"北京","path":"中国, 北京, 北京"},"now":{"precipitation":0.0,"temperature":24.5,"pressure":1006.0,"humidity":34.0,"windDirection":"西南风","windDirectionDegree":191.0,"windSpeed":2.8,"windScale":"微风"},"alarm":[],"lastUpdate":"2025/04/20 15:35"}}'}] >>> tool_call: ChatCompletionMessageToolCall(id='call_ae1c0c869cbf', functinotallow=Function(arguments='{"location": "广州"}', name='get_weather'), type='function', index=0) >>> tool_call result: {'role': 'tool', 'tool_call_id': 'call_ae1c0c869cbf', 'content': '{"msg":"success","code":0,"data":{"location":{"id":"59287","name":"广州","path":"中国, 广东, 广州"},"now":{"precipitation":0.0,"temperature":30.4,"pressure":1001.0,"humidity":64.0,"windDirection":"东南风","windDirectionDegree":165.0,"windSpeed":2.2,"windScale":"微风"},"alarm":[],"lastUpdate":"2025/04/20 15:35"}}'} >> iterSeq:3 >>> messages: [{'role': 'user', 'content': '北京和广州天气怎么样'}, {'role': 'assistant', 'tool_calls': [ChatCompletionMessageToolCall(id='call_dbad99d', functinotallow=Function(arguments='{"location": "北京"}', name='get_weather'), type='function', index=0)], 'content': ''}, {'role': 'tool', 'tool_call_id': 'call_dbad99d', 'content': '{"msg":"success","code":0,"data":{"location":{"id":"54511","name":"北京","path":"中国, 北京, 北京"},"now":{"precipitation":0.0,"temperature":24.5,"pressure":1006.0,"humidity":34.0,"windDirection":"西南风","windDirectionDegree":191.0,"windSpeed":2.8,"windScale":"微风"},"alarm":[],"lastUpdate":"2025/04/20 15:35"}}'}, {'role': 'assistant', 'tool_calls': [ChatCompletionMessageToolCall(id='call_ae1c0c869cbf', functinotallow=Function(arguments='{"location": "广州"}', name='get_weather'), type='function', index=0)], 'content': ''}, {'role': 'tool', 'tool_call_id': 'call_ae1c0c869cbf', 'content': '{"msg":"success","code":0,"data":{"location":{"id":"59287","name":"广州","path":"中国, 广东, 广州"},"now":{"precipitation":0.0,"temperature":30.4,"pressure":1001.0,"humidity":64.0,"windDirection":"东南风","windDirectionDegree":165.0,"windSpeed":2.2,"windScale":"微风"},"alarm":[],"lastUpdate":"2025/04/20 15:35"}}'}] >>> final result: 北京的当前天气状况如下： - 温度：24.5°C - 湿度：34% - 风向：西南风 - 风速：微风 (2.8 m/s) - 最后更新时间：2025/04/20 15:35 广州的当前天气状况如下： - 温度：30.4°C - 湿度：64% - 风向：东南风 - 风速：微风 (2.2 m/s) - 最后更新时间：2025/04/20 15:35