Claude 3 Opus Tool Use 与 Function Calling 完整对比：2025开发者必看指南

pip install requests anthropic

步骤 3：完整代码实现

# weather_bot.py - 基于 Claude Tool Use 的天气机器人
import requests
import json

class WeatherBot:
    def __init__(self, api_key):
        self.api_key = api_key
        self.base_url = "https://api.holysheep.ai/v1/messages"
        
    def get_weather(self, city):
        """模拟天气查询（真实项目这里调第三方API）"""
        weather_data = {
            "北京": {"temp": 22, "condition": "晴", "humidity": 45},
            "上海": {"temp": 25, "condition": "多云", "humidity": 60},
            "广州": {"temp": 28, "condition": "雷阵雨", "humidity": 80}
        }
        return weather_data.get(city, {"temp": 20, "condition": "未知", "humidity": 50})
    
    def chat(self, user_message):
        headers = {
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json",
            "Anthropic-Version": "2023-06-01"
        }
        
        tools = [{
            "name": "get_weather",
            "description": "查询城市天气，返回温度、天气状况和湿度",
            "input_schema": {
                "type": "object",
                "properties": {
                    "city": {"type": "string", "description": "要查询的城市名"}
                },
                "required": ["city"]
            }
        }]
        
        payload = {
            "model": "claude-sonnet-4-5",
            "max_tokens": 1024,
            "tools": tools,
            "messages": [{"role": "user", "content": user_message}]
        }
        
        response = requests.post(self.base_url, headers=headers, json=payload)
        result = response.json()
        
        # 检查是否需要调用工具
        if "content" in result:
            for block in result["content"]:
                if block.get("type") == "tool_use":
                    tool_name = block["name"]
                    tool_input = block["input"]
                    
                    if tool_name == "get_weather":
                        city = tool_input.get("city", "")
                        weather = self.get_weather(city)
                        
                        # 将工具结果返回给 Claude 生成最终回复
                        return self._continue_conversation(result, block, weather, user_message)
        
        return result.get("content", [{"text": "抱歉，出错了"}])
    
    def _continue_conversation(self, initial_result, tool_block, tool_result, original_message):
        """将工具调用结果反馈给 Claude，获取最终回复"""
        headers = {
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json",
            "Anthropic-Version": "2023-06-01"
        }
        
        # 构建包含工具结果的完整对话
        messages = [
            {"role": "user", "content": original_message},
            {"role": "assistant", "content": initial_result.get("content", [])},
            {
                "role": "user", 
                "content": [{
                    "type": "tool_result",
                    "tool_use_id": tool_block["id"],
                    "content": json.dumps(tool_result)
                }]
            }
        ]
        
        payload = {
            "model": "claude-sonnet-4-5",
            "max_tokens": 1024,
            "messages": messages
        }
        
        response = requests.post(self.base_url, headers=headers, json=payload)
        return response.json()

使用示例
if __name__ == "__main__":
    bot = WeatherBot("YOUR_HOLYSHEEP_API_KEY")
    reply = bot.chat("北京今天适合穿什么出门？")
    print(reply)

步骤 4：运行测试

python weather_bot.py

正常情况下你会看到 Claude 返回的完整天气信息和出行建议。

常见报错排查

错误 1：401 Unauthorized - API Key 无效

# ❌ 错误示例
headers = {
    "Authorization": "Bearer YOUR_HOLYSHEEP_API_KEY"  # 忘记替换
}

✅ 正确写法
headers = {
    "Authorization": f"Bearer {api_key}"  # 从变量读取
}

解决：检查 API Key 是否正确复制，确保没有多余空格。如果 Key 过期，去 HolySheep 控制台重新生成。

错误 2：400 Bad Request - 工具定义格式错误

# ❌ 常见错误：required 字段写错位置
{
    "name": "get_weather",
    "input_schema": {
        "type": "object",
        "required": ["city"],  # required 应该在 properties 外面
        "properties": {
            "city": {"type": "string"}
        }
    }
}

✅ 正确格式
{
    "name": "get_weather", 
    "input_schema": {
        "type": "object",
        "properties": {
            "city": {"type": "string"}
        },
        "required": ["city"]
    }
}

解决：对照官方 schema 格式检查，required 数组必须和 properties 平级。

错误 3：504 Gateway Timeout - 请求超时

这是国内访问海外 API 的老问题了。用 HolySheep 可以完美解决，因为它是国内直连节点。

# ❌ 官方 API（经常超时）
url = "https://api.anthropic.com/v1/messages"  # 海外节点

✅ HolySheep（国内直连，<50ms）
url = "https://api.holysheep.ai/v1/messages"

如果必须用官方 API，可以设置超时重试：

import time

def call_with_retry(url, payload, max_retries=3):
    for i in range(max_retries):
        try:
            response = requests.post(url, json=payload, timeout=30)
            return response.json()
        except requests.exceptions.Timeout:
            if i < max_retries - 1:
                time.sleep(2 ** i)  # 指数退避
            continue
    return {"error": "Max retries exceeded"}

错误 4：tool_use 块没有正确解析

# ❌ 只检查 content 存在，没有遍历 block 类型
if "content" in result:
    text = result["content"][0]["text"]  # 如果是 tool_use 会报错

✅ 正确遍历所有 content block
if "content" in result:
    for block in result["content"]:
        if block["type"] == "text":
            final_answer = block["text"]
        elif block["type"] == "tool_use":
            tool_name = block["name"]
            tool_args = block["input"]
            # 处理工具调用...

总结与购买建议

Tool Use 和 Function Calling 本质上解决的是同一个问题——让 AI 调用外部工具。Claude 的 Tool Use 更智能，适合复杂场景；传统 Function Calling 更简单，适合快速开发。

如果你正在评估采购方案，我的建议是：