title: Django multi user handling
body: <p>I’m writing an app which a user can calculate some values and get a graph from them.</p>
  <p>I thought what would happen when multiple users fire a request for calculating?
  I can store variables in session but I’m not sure what will happen when multiple users fire a method at the same time.</p>
  <p>Eg.</p>
  <pre class="lang-py prettyprint-override"><code>def calc(self,x,y):
  test = []
  test.append(…)
  </code></pre>