如何获取boto以生成触发下载的S3的签名URL？

I've attempted this:

我试过这个：

connection = S3Connection(
    aws_access_key_id=settings.AWS_ACCESS_KEY_ID,
    aws_secret_access_key=settings.AWS_SECRET_ACCESS_KEY)

url = connection.generate_url(
    60,
    'GET',
    settings.AWS_STORAGE_BUCKET_NAME,
    self.get_object().image,
    headers={'Content-Type': 'application/octet-stream'})
connection = S3