以下是一个示例代码，用于将用户活动按照连续时间分组：

from datetime import datetime, timedelta

def group_activities_by_time(activities):
    groups = []
    current_group = [activities[0]]  # 创建第一个分组
    
    for i in range(1, len(activities)):
        current_activity = activities[i]
        previous_activity = activities[i-1]
        
        current_time = datetime.strptime(current_activity['time'], '%Y-%m-%d %H:%M:%S')
        previous_time = datetime.strptime(previous_activity['time'], '%Y-%m-%d %H:%M:%S')
        
        time_difference = current_time - previous_time
        
        # 判断当前活动和前一个活动是否连续
        if time_difference <= timedelta(hours=1):
            current_group.append(current_activity)
        else:
            groups.append(current_group)
            current_group = [current_activity]  # 创建新的分组
    
    groups.append(current_group)  # 添加最后一个分组
    
    return groups

# 示例数据
activities = [
    {'activity': 'A', 'time': '2022-01-01 10:00:00'},
    {'activity': 'B', 'time': '2022-01-01 11:00:00'},
    {'activity': 'C', 'time': '2022-01-01 14:00:00'},
    {'activity': 'D', 'time': '2022-01-01 15:00:00'},
    {'activity': 'E', 'time': '2022-01-01 16:00:00'},
    {'activity': 'F', 'time': '2022-01-01 18:00:00'},
]

groups = group_activities_by_time(activities)
for group in groups:
    print(group)

输出结果为：

[{'activity': 'A', 'time': '2022-01-01 10:00:00'}, {'activity': 'B', 'time': '2022-01-01 11:00:00'}]
[{'activity': 'C', 'time': '2022-01-01 14:00:00'}, {'activity': 'D', 'time': '2022-01-01 15:00:00'}, {'activity': 'E', 'time': '2022-01-01 16:00:00'}]
[{'activity': 'F', 'time': '2022-01-01 18:00:00'}]

该示例代码通过比较当前活动和前一个活动的时间差，将连续的活动分为同一组。时间差小于等于1小时的活动被视为连续活动。每次遇到不连续的活动时，将当前分组添加到结果列表中，并创建一个新的空分组。最后，将最后一个分组添加到结果列表中。