title: gcp: testing an application which uses ndb (no module named `google.appengine`)
body: <p>I have a GAE application in python3, which uses datastore ndb client libraries. Is there a way to test it locally or with dev_appserver.py ?</p>
  
  <p>Namely, is there a way to satisfy the <code>google.appengine.ext.ndb</code> import locally or via some mock/shim layer? Maybe I'm missing a module in my requirements.txt, not sure which.</p>
  
  <p><a href="https://cloud.google.com/appengine/docs/standard/python3/testing-and-deploying-your-app" rel="nofollow noreferrer"><code>dev_appserver.py --application my_application app.yaml</code></a> fails. The local server starts, but then it can't bring up the application because it fails early on in the imports with <code>ImportError: No module named 'google.appengine'</code>. </p>
  
  <p>In case this is a requirements issue, I currently have: <code>google-cloud-datastore==1.7.1</code> in my <code>requirements.txt</code> file. Working examples for python3 are hard to come by.</p>