如何将Google Drive下载输出流保存为文件？

import io
from googleapiclient.discovery import build
from googleapiclient.http import MediaIoBaseDownload

# 创建Google Drive API客户端
drive_service = build('drive', 'v3', credentials=credentials)

# 文件ID，即要下载的文件在Google Drive中的唯一标识符
file_id = 'your_file_id'

# 创建一个BytesIO对象，用于保存下载的文件内容
file_stream = io.BytesIO()

# 创建文件下载请求
request = drive_service.files().get_media(fileId=file_id)

# 将文件内容下载到BytesIO对象中
downloader = MediaIoBaseDownload(file_stream, request)
done = False
while done is False:
    status, done = downloader.next_chunk()

# 将文件内容保存到本地文件
with open('output_file', 'wb') as f:
    f.write(file_stream.getvalue())