如何从集合中获取用户id

users = [
    {"id": 1, "name": "Alice"},
    {"id": 2, "name": "Bob"},
    {"id": 3, "name": "Charlie"}
]

# 获取所有用户ID
user_ids = [user["id"] for user in users]
print(user_ids)  # 输出: [1, 2, 3]

user_ids_set = {1, 2, 3, 4, 5}

# 获取所有用户ID（集合本身已经是用户ID的集合）
print(user_ids_set)  # 输出: {1, 2, 3, 4, 5}

users_dict = {
    1: {"name": "Alice"},
    2: {"name": "Bob"},
    3: {"name": "Charlie"}
}

# 获取所有用户ID
user_ids_dict = list(users_dict.keys())
print(user_ids_dict)  # 输出: [1, 2, 3]

users = [
    {"id": 1, "name": "Alice", "age": 25},
    {"id": 2, "name": "Bob", "age": 30},
    {"id": 3, "name": "Charlie", "age": 20}
]

# 获取年龄大于25的用户ID
user_ids_above_25 = [user["id"] for user in users if user["age"] > 25]
print(user_ids_above_25)  # 输出: [2]