title: Google Clode Datastore Client Library creating an entity
body: <p>I'm working through some documentation for the google cloud datastore API</p>
  
  <p>Namely <a href="https://googleapis.github.io/google-cloud-python/latest/datastore/client.html" rel="nofollow noreferrer">https://googleapis.github.io/google-cloud-python/latest/datastore/client.html</a>
  and 
  <a href="https://googleapis.github.io/google-cloud-python/latest/_modules/google/cloud/datastore/entity.html#Entity" rel="nofollow noreferrer">https://googleapis.github.io/google-cloud-python/latest/_modules/google/cloud/datastore/entity.html#Entity</a></p>
  
  <p>Using both sources I've created the following. I'm extremely confused by client.key(), namely the 1234 and namespace. My datastore shows the keys which seems to be a random? unique number and I have not seen any reference to a namespace. Why is this code sample specifying an integer and a namespace? Is there a better way to generate a key or can these two parameters be safely omitted?</p>
  
  <pre><code>    from google.cloud import datastore
      client = datastore.Client()
      key = client.key('Collection', 1234, namespace='_Doctest')
      entity = datastore.Entity(key=key)
      entity['property'] = 'value'
      client.put(entity)
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/jmXz0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jmXz0.png" alt="key description"></a></p>