如何拆分字典内列表中的字典并单独处理其中的值？

我清楚自己需要掌握字典（Dictionary）和列表推导式（List Comprehension）的相关知识。我在Stack Overflow等平台查了很多文章，但越看越懵，希望有人能帮忙。

当我查询数据库时，会得到一个<class 'dict'>类型的对象，格式是{'results': [ {x1:1, y1:2, z1:3}, {...}, {...} ]}，示例如下：

{'results': [{'Event Time': '2023-01-25T00:18:32.3900000', 'AccountID': 'MICROSOFT\\Norma.Cayshun', 'AuditEventMessage': 'User MICROSOFT\\Norma.Cayshun has changed alert note SOUTHBAY-VM2 13.107.136.45 has rebooted. [].'}, {'Event Time': '2023-01-25T00:18:32.3900000', 'AccountID': 'MICROSOFT\\Norma.Cayshun', 'AuditEventMessage': 'User MICROSOFT\\Norma.Cayshun acknowledged alert SOUTHBAY-VM2 13.107.136.45 has rebooted..'}, {'Event Time': '2023-01-16T01:55:05.1930000', 'AccountID': 'MICROSOFT\\Christopher.Cheef', 'AuditEventMessage': 'User MICROSOFT\\Christopher.Cheef has changed alert note Server Node Down on NORTHLOBBY-VM5 [].'}, {'Event Time': '2023-01-16T01:55:05.1930000', 'AccountID': 'MICROSOFT\\Christopher.Cheef', 'AuditEventMessage': 'User MICROSOFT\\Christopher.Cheef acknowledged alert Server Node Down on NORTHLOBBY-VM5.'}, {'Event Time': '2023-01-16T01:55:05.1930000', 'AccountID': 'MICROSOFT\\Christopher.Cheef', 'AuditEventMessage': 'User MICROSOFT\\Christopher.Cheef has changed alert note SOUTHBAY-VM2 13.107.136.45 has rebooted. [].'}]}

我希望把这些字典里的值单独提取出来，格式化打印或者按需处理，比如：

1. 'Event Time': '2023-01-25T00:18:32.3900000', 'AccountID': 'MICROSOFT\\Norma.Cayshun', 'AuditEventMessage': 'User MICROSOFT\\Norma.Cayshun has changed alert note SOUTHBAY-VM2 13.107.136.45 has rebooted. [].'

2. 'Event Time': '2023-01-25T00:18:32.3900000', 'AccountID': 'MICROSOFT\\Norma.Cayshun', 'AuditEventMessage': 'User MICROSOFT\\Norma.Cayshun acknowledged alert SOUTHBAY-VM2 13.107.136.45 has rebooted..'

3. 'Event Time': '2023-01-16T01:55:05.1930000', 'AccountID': 'MICROSOFT\\Christopher.Cheef', 'AuditEventMessage': 'User MICROSOFT\\Christopher.Cheef has changed alert note Server Node Down on NORTHLOBBY-VM5 [].'

有人推荐用Pandas/Numpy、Zip()、Lambda()这些方法，但我想要更简单的方案，这样能更好理解问题。以下是我正在测试的代码：

def query_database():
    result = {'results': [{'Event Time': '2023-01-25T00:18:32.3900000', 'AccountID': 'MICROSOFT\\Norma.Cayshun', 'AuditEventMessage': 'User MICROSOFT\\Norma.Cayshun has changed alert note SOUTHBAY-VM2 13.107.136.45 has rebooted. [].'}, {'Event Time': '2023-01-25T00:18:32.3900000', 'AccountID': 'MICROSOFT\\Norma.Cayshun', 'AuditEventMessage': 'User MICROSOFT\\Norma.Cayshun acknowledged alert SOUTHBAY-VM2 13.107.136.45 has rebooted..'}, {'Event Time': '2023-01-16T01:55:05.1930000', 'AccountID': 'MICROSOFT\\Christopher.Cheef', 'AuditEventMessage': 'User MICROSOFT\\Christopher.Cheef has changed alert note Server Node Down on NORTHLOBBY-VM5 [].'}, {'Event Time': '2023-01-16T01:55:05.1930000', 'AccountID': 'MICROSOFT\\Christopher.Cheef', 'AuditEventMessage': 'User MICROSOFT\\christopher.Cheef acknowledged alert Server Node Down on NORTHLOBBY-VM5.'}, {'Event Time': '2023-01-16T01:55:05.1930000', 'AccountID': 'MICROSOFT\\Christopher.Cheef', 'AuditEventMessage': 'User MICROSOFT\\Christopher.Cheef has changed alert note SOUTHBAY-VM2 13.107.136.45 has rebooted. [].'}]}
    return result


def display_data():
    result = query_database()
    print("{0}".format(result))

    for item in result:
        print(item)
        print(f">>> {result.values()}")


def main():
    display_data()

if __name__ == '__main__':
    main()

你的核心问题是没正确访问到嵌套在字典里的列表。外层字典只有一个键'results'，对应的值是你需要处理的字典列表。我们可以用基础的循环来实现需求：

修改display_data函数如下：

def display_data():
    result = query_database()
    # 获取results对应的列表
    events = result['results']
    # 遍历列表，用enumerate获取索引（从1开始）和每个事件字典
    for idx, event in enumerate(events, start=1):
        # 把字典转换成符合要求的字符串格式
        event_str = ", ".join([f"'{k}': '{v}'" for k, v in event.items()])
        # 打印带编号的结果
        print(f"{idx}. {event_str}\n")

代码解释 #

1. result['results']：直接取出外层字典里的列表，这是你要处理的核心数据。
2. enumerate(events, start=1)：遍历列表时同时获取从1开始的编号，正好对应你想要的1、2、3...格式。
3. ", ".join([f"'{k}': '{v}'" for k, v in event.items()])：把每个事件字典的键值对转换成指定的字符串格式，再用逗号连接起来。
4. 最后用print(f"{idx}. {event_str}\n")输出带编号的结果，每个条目后换行分开。

这样修改后，运行代码就能得到你想要的格式化输出，而且都是基础的字典和列表操作，容易理解。

内容的提问来源于stack exchange，提问作者AliasSyed