如何向CoinMarketCap API发送逗号分隔资产列表进行价格转换

官方API文档说明，price-conversion接口支持传递最多120个逗号分隔的法币或加密货币符号，通过单次API调用即可获取多资产的价格转换结果，且仅消耗1个调用额度。但直接传入资产列表会返回400错误，循环逐个调用又会消耗多个额度，不符合预期。

以下是两种无效的尝试代码：

无效代码1：直接传入资产列表 #

from requests import Session
from requests.exceptions import ConnectionError, Timeout, TooManyRedirects

def usdPrice(assets):
    url = 'https://pro-api.coinmarketcap.com/v2/tools/price-conversion'
    parameters = {
        'amount' : 1,
        'symbol': assets,  # 直接传列表会导致400错误
        'convert' : 'USD'
    }
    headers = {
        'Accepts': 'application/json',
        'X-CMC_PRO_API_KEY': cmcKey,
    }
    session = Session()
    session.headers.update(headers)
    try:
        response = session.get(url, params=parameters)
        print(response)
        data = response.json().get("data")
        print(data)
    except (ConnectionError, Timeout, TooManyRedirects) as e:
        print(e)

assets = ['BTC','XRP','LTC']
usdPrice(assets)

无效代码2：循环逐个调用API #

from requests import Session
from requests.exceptions import ConnectionError, Timeout, TooManyRedirects

def usdPrice(assets):
    url = 'https://pro-api.coinmarketcap.com/v2/tools/price-conversion'
    for i in assets:
        parameters = {
            'amount' : 1,
            'symbol': i,
            'convert' : 'USD'
        }
        headers = {
            'Accepts': 'application/json',
            'X-CMC_PRO_API_KEY': cmcKey,
        }
        session = Session()
        session.headers.update(headers)
        try:
            response = session.get(url, params=parameters)
            print(response)
            data = response.json().get("data")
            print(data)
        except (ConnectionError, Timeout, TooManyRedirects) as e:
            print(e)

assets = ['BTC','XRP','LTC']
usdPrice(assets)

正确解决方案 #

核心问题是需要将资产列表转换为逗号分隔的字符串传入symbol参数，而不是直接传Python列表。修改后的代码如下：

from requests import Session
from requests.exceptions import ConnectionError, Timeout, TooManyRedirects

def usdPrice(assets):
    url = 'https://pro-api.coinmarketcap.com/v2/tools/price-conversion'
    # 将列表转为逗号分隔的字符串
    symbol_str = ','.join(assets)
    parameters = {
        'amount' : 1,
        'symbol': symbol_str,  # 传入格式化后的字符串
        'convert' : 'USD'
    }
    headers = {
        'Accepts': 'application/json',
        'X-CMC_PRO_API_KEY': cmcKey,  # 请确保cmcKey已正确定义
    }
    session = Session()
    session.headers.update(headers)
    try:
        response = session.get(url, params=parameters)
        print(response.status_code)
        data = response.json().get("data")
        # 遍历返回的多资产数据
        for item in data:
            symbol = item['symbol']
            price = item['quote']['USD']['price']
            print(f"{symbol}: ${price:.2f}")
    except (ConnectionError, Timeout, TooManyRedirects) as e:
        print(e)

assets = ['BTC','XRP','LTC']
usdPrice(assets)

关键修改点： #

• 使用','.join(assets)将资产列表转换为API要求的逗号分隔格式字符串
• 单次调用API即可获取所有资产的转换结果，仅消耗1个额度
• 处理返回数据时，遍历data数组即可拿到每个资产的价格信息

内容的提问来源于stack exchange，提问作者nodeidea