title: How to get list_blobs to behave like gsutil
body: <p>I would like to only get the first level of a fake folder structure on GCS.</p>
  
  <p>If I run e.g.:</p>
  
  <p><code>
  gsutil ls 'gs://gcp-public-data-sentinel-2/tiles/'
  </code>
  I get a list like this:
  <code>
  gs://gcp-public-data-sentinel-2/tiles/01/
  gs://gcp-public-data-sentinel-2/tiles/02/
  gs://gcp-public-data-sentinel-2/tiles/03/
  gs://gcp-public-data-sentinel-2/tiles/04/
  gs://gcp-public-data-sentinel-2/tiles/05/
  gs://gcp-public-data-sentinel-2/tiles/06/
  gs://gcp-public-data-sentinel-2/tiles/07/
  gs://gcp-public-data-sentinel-2/tiles/08/
  gs://gcp-public-data-sentinel-2/tiles/09/
  gs://gcp-public-data-sentinel-2/tiles/10/
  gs://gcp-public-data-sentinel-2/tiles/11/
  gs://gcp-public-data-sentinel-2/tiles/12/
  gs://gcp-public-data-sentinel-2/tiles/13/
  gs://gcp-public-data-sentinel-2/tiles/14/
  gs://gcp-public-data-sentinel-2/tiles/15/
  .
  .
  .
  </code></p>
  
  <p>Running code like the following in the Python API give me an empty result:</p>
  
  <pre><code>from google.cloud import storage
  bucket_name = 'gcp-public-data-sentinel-2'
  prefix = 'tiles/'
  storage_client = storage.Client()
  bucket = storage_client.get_bucket(bucket_name)
  for blob in bucket.list_blobs(max_results=10, prefix=prefix,
                                delimiter='/'):
      print blob.name
  </code></pre>
  
  <p>If I don't use the <code>delimiter</code> option I get all the results in the bucket which is not very useful.</p>