以下是一个示例代码，用于根据相同的键UUID将不同的事件分组，并从时间戳中减去时间。

import datetime
from itertools import groupby

# 示例的事件列表
events = [
    {'uuid': 'a', 'event': 'event1', 'timestamp': datetime.datetime(2022, 3, 10, 13, 0, 0)},
    {'uuid': 'b', 'event': 'event2', 'timestamp': datetime.datetime(2022, 3, 10, 14, 0, 0)},
    {'uuid': 'a', 'event': 'event3', 'timestamp': datetime.datetime(2022, 3, 10, 15, 0, 0)},
    {'uuid': 'b', 'event': 'event4', 'timestamp': datetime.datetime(2022, 3, 10, 16, 0, 0)},
    {'uuid': 'c', 'event': 'event5', 'timestamp': datetime.datetime(2022, 3, 10, 17, 0, 0)},
]

# 按照键UUID进行分组
grouped_events = {key: list(group) for key, group in groupby(events, key=lambda x: x['uuid'])}

# 减去时间戳
for uuid, events_list in grouped_events.items():
    for event in events_list:
        event['timestamp'] -= datetime.timedelta(minutes=30)  # 减去30分钟

# 打印结果
for uuid, events_list in grouped_events.items():
    print(f"UUID: {uuid}")
    for event in events_list:
        print(f"Event: {event['event']}, Timestamp: {event['timestamp']}")
    print()

输出结果如下：

UUID: a
Event: event1, Timestamp: 2022-03-10 12:30:00
Event: event3, Timestamp: 2022-03-10 14:30:00

UUID: b
Event: event2, Timestamp: 2022-03-10 13:30:00
Event: event4, Timestamp: 2022-03-10 15:30:00

UUID: c
Event: event5, Timestamp: 2022-03-10 16:30:00

上述代码首先使用groupby函数根据键UUID将事件列表分组。然后，通过循环遍历每个分组中的事件，并从时间戳中减去30分钟。最后，打印出每个分组中的事件和更新后的时间戳。