ValueError: too many values to unpack (expected 2) with a list of tuples in Python

Question

我在使用 Python 创建代码时遇到了这个问题。我传递了一个元组列表，但是在解压缩它然后使用 map 函数然后使用列表时。我收到此错误：

ValueError：要解压的值太多（预期为 2）

知道如何克服这个问题吗？我找不到与元组列表相关的合适答案:-(

这是代码

stock_markets = [('AAPL','200'),('MSFT','780'),('ORCL','650'),('CISC','350')]

def analyze_stocks(stock_markets):
    current_max = 0
    stock_name = ''

    for company,price in stock_markets:
        if int(price) > current_max:
            current_max = int(price)
            stock_name = company
        else:
            pass

    return (stock_name, current_max)

list(map(analyze_stocks,stock_markets))

Answer 1

您已经使用 map 遍历列表。分析函数中的 for 循环是不需要的（因为您已经使用 map 一个一个地传递了您的股票），它是错误的来源。正确的版本应该是这样的：

stock_markets = [('AAPL','200'),('MSFT','780'),('ORCL','650'),('CISC','350')]

def analyze_stocks(stock_markets):
    current_max = 0
    stock_name = ''

    company, price = stock_markets
    if int(price) > current_max:
        current_max = int(price)
        stock_name = company

    return (stock_name, current_max)

list(map(analyze_stocks,stock_markets))

ValueError: too many values to unpack (expected 2) with a list of tuples in Python

ValueError: too many values to unpack (expected 2) with a list of tuples in Python

python

tuples

list

iterable-unpacking