让 API 工具调用更健壮

在生产环境中，如果汇率 API 缓慢或不可达，货币服务器的 convert_currency() 工具不应一直挂起。为此，您将为请求实现一个超时，并确保任何失败都向用户返回简短清晰的错误信息，而不是原始异常。

一个 MCP 服务器已实例化并存储在变量 mcp 中。

本练习是课程的一部分

Model Context Protocol (MCP) 入门

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练习说明

实现 try-except 逻辑：尝试发起 API 请求；一旦出错，捕获异常并优雅地失败。
在 requests.get() 调用中添加 10 秒超时（timeout=10），避免请求无限期挂起。

交互式实操练习

通过完成这段示例代码来试试这个练习。

@mcp.tool()
def convert_currency(amount: float, from_currency: str, to_currency: str) -> str:
    """
    Convert an amount from one currency to another using current exchange rates.

    Args:
        amount: The amount to convert
        from_currency: Source currency code (e.g., 'USD', 'EUR', 'GBP')
        to_currency: Target currency code (e.g., 'USD', 'EUR', 'GBP')

    Returns:
        A string with the conversion result and exchange rate
    """
    url = f"https://api.frankfurter.dev/v1/latest?base={from_currency}&symbols={to_currency}"
    # Implement try-except to gracefully handle errors
    ____:
        # Add a 10-second timeout so the request does not hang
        r = requests.get(url, ____=____)
        r.raise_for_status()
        data = r.json()
        rate = data["rates"].get(to_currency)
        if rate is None:
            return f"Could not find exchange rate for {from_currency} to {to_currency}"
        return f"{amount} {from_currency} = {amount * rate:.2f} {to_currency} (Rate: {rate})"
    ____ requests.exceptions.RequestException as e:
        return f"Error converting currency: {e}"

print(convert_currency(10, "USD", "EUR"))

编辑并运行代码