title: Django delete cache with specific key_prefix
body: <p>I'm using Django's per-view <code>@cache_page</code> decorator and have set a different <code>key_prefix</code> for each view.</p>
  
  <p>I've previously deleted the cache with:</p>
  
  <pre><code>from django.core.cache import cache
  cache.clear()
  </code></pre>
  
  <p>But what if I just want to delete the keys containing a specific <code>key_prefix</code>? I can obviously do it by just connecting to the database and delete with raw sql but I wonder if it can be done with 'pure' Django?</p>
  
  <p>I'm using a database cache, not a memory cache.</p>
  
  <p>I'm using Django 1.11 and Python 3.6</p>