title: How to check if string contains chars which are not in a list?
body: <p>I have a question. How do I check if a python string contains chars which are not in a given list?</p>
  <p>Here is the list (set):</p>
  <pre class="lang-py prettyprint-override"><code>set(&quot;ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._&quot;)
  </code></pre>