title: Download blob from gcp storage bucket with python flask
body: <p>I have a GCP bucket with some pdf files.
  I am able to download the files from bucket with python(flask) on local host using below code -</p>
  <pre><code>storage_client = storage.Client.from_service_account_json(&quot;ebillaae7f0224519.json&quot;)
  bucket = storage_client.get_bucket(&quot;bill_storage1&quot;)
  blob = bucket.blob(file_name)
  blob.download_to_filename(&quot;file1.pdf&quot;)
  </code></pre>
  <p>But when deployed on GCP(app engine) i get this error &quot;line 1282, in download_to_filename with open(filename, &quot;wb&quot;) as file_obj: OSError: [Errno 30] Read-only file system: 'file1.pdf'&quot;
  Then i modified code to -</p>
  <pre><code>storage_client = storage.Client.from_service_account_json(&quot;ebillaae7f0224519.json&quot;)
  bucket = storage_client.get_bucket(&quot;bill_storage1&quot;)
  blob = bucket.blob(file_name)
  blob.download_to_filename(&quot;/tmp/file1.pdf&quot;)
  </code></pre>
  <p>This works after deployment but i cant download the files from bucket to local folder through my app, how to do that?</p>