title: Python3 index of char on String when not found
body: <p>As said in the official <a href="https://docs.python.org/3/library/stdtypes.html#string-methods" rel="nofollow noreferrer">documentation</a>, in Python when calling the function <code>index</code> on a String</p>
  
  <blockquote>
    <p>index raises ValueError when x is not found in s</p>
  </blockquote>
  
  <p>I know we can test the existence of a char in a String simply like this <code>'c' in String</code>, but it makes the syntax kind of akward. </p>
  
  <p>Is there any known implementation of the function <code>index</code> that would return a -1 or such an error code instead of raising an <code>Error</code></p>