列表和索引

1# 使用不同数据类型的列表
2server_ids = [101, 102, 103, 104]
3mixed_config = ["production", 8080, True, 3.11]
4empty_list = []
5
6print(f"服务器: {server_ids}")
7print(f"配置: {mixed_config}")
8print(f"空列表: {empty_list}")
9print(f"空列表类型: {type(empty_list)}")

1# 使用正索引访问元素
2colors = ["red", "green", "blue", "yellow"]
3
4primary = colors[0]
5secondary = colors[2]
6
7print(f"第一个颜色: {primary}")
8print(f"第三个颜色: {secondary}")

1# 从列表末尾访问元素
2file_paths = ["/bin", "/usr", "/etc", "/var", "/home"]
3
4last_path = file_paths[-1]
5second_last = file_paths[-2]
6
7print(f"最后一个路径: {last_path}")
8print(f"倒数第二个: {second_last}")

1# 使用切片提取子列表
2metrics = [10, 20, 30, 40, 50, 60, 70, 80]
3
4first_three = metrics[0:3]
5middle_segment = metrics[3:6]
6every_second = metrics[::2]
7reverse_metrics = metrics[::-1]
8
9print(f"前三个: {first_three}")
10print(f"中间段: {middle_segment}")
11print(f"每隔一个: {every_second}")
12print(f"反转后: {reverse_metrics}")

1# 就地修改列表元素
2user_roles = ["admin", "editor", "viewer", "guest"]
3# 先打印原始 ID
4print(f"原始 ID: {id(user_roles)}")
5# 先打印原始角色
6print(f"原始角色: {user_roles}")
7
8# 更新切片（替换多个元素）
9user_roles[0:2] = ["superuser", "moderator"]
10
11# 替换元素后打印 ID
12print(f"相同 ID:     {id(user_roles)}")
13# 替换元素后打印角色
14print(f"更新后的角色: {user_roles}")