要在不复制对象的情况下更改AWS S3存储类，可以使用AWS SDK提供的copy_object()函数来实现。以下是一个示例代码，演示了如何更改存储类。

import boto3

def change_storage_class(bucket_name, object_key, new_storage_class):
    # 创建S3客户端
    s3 = boto3.client('s3')

    # 获取当前对象的元数据
    response = s3.head_object(Bucket=bucket_name, Key=object_key)
    current_storage_class = response['StorageClass']

    # 如果当前存储类与新存储类相同，则无需更改
    if current_storage_class == new_storage_class:
        print("存储类已是所需的存储类。")
        return

    # 复制对象并更改存储类
    response = s3.copy_object(
        Bucket=bucket_name,
        CopySource={'Bucket': bucket_name, 'Key': object_key},
        Key=object_key,
        StorageClass=new_storage_class
    )

    # 验证复制操作是否成功
    if response['ResponseMetadata']['HTTPStatusCode'] == 200:
        print("存储类已成功更改。")
    else:
        print("存储类更改失败。")

# 示例用法
bucket_name = 'your-bucket-name'
object_key = 'your-object-key'
new_storage_class = 'STANDARD_IA'  # 新的存储类

change_storage_class(bucket_name, object_key, new_storage_class)

注意：在使用此代码之前，确保已安装适当的AWS SDK并配置了有效的凭据。