title: aws s3 bucket search subfolders
body: <p>The article in the following link</p>
  
  <pre><code>https://alexwlchan.net/2017/07/listing-s3-keys/
  </code></pre>
  
  <p>helps as far as objects are in parent folder
  How will it be possible to accomplish to also read objects in subfolders
  I tried to use <code>mybucket.objects.filter(Prefix=someprefix)</code> but it wont look for objects in subfolders
  <code>mybucket.objects.all()</code> will work(it looks into subfolders as well) but when there are millions of files in a bucket,the calling lambda function will timeout</p>