Youtube api -how从函数返回下一页标记？

import googleapiclient.discovery

# 创建YouTube API客户端
youtube = googleapiclient.discovery.build('youtube', 'v3', developerKey='YOUR_API_KEY')

def search_videos(query, page_token=None):
    # 构建搜索请求
    search_request = youtube.search().list(
        q=query,
        part='snippet',
        maxResults=10,
        pageToken=page_token
    )

    # 发送搜索请求
    search_response = search_request.execute()

    # 获取搜索结果
    videos = search_response['items']

    # 获取下一页的标记
    next_page_token = search_response.get('nextPageToken')

    return videos, next_page_token

# 搜索视频并获取第一页结果
results, next_page_token = search_videos('cats')

# 打印第一页结果
for video in results:
    print(video['snippet']['title'])

# 搜索下一页结果
results, next_page_token = search_videos('cats', page_token=next_page_token)

# 打印下一页结果
for video in results:
    print(video['snippet']['title'])