title: TypeError: 'int' object is not iterable error in python
body: <pre><code>counter = 0
  for i in len(s):
      if i in ('a','e','i','o','u'):
          counter += 1
  print(&quot;Number of vowels:&quot; + str(counter))
  </code></pre>
  <p>I'm trying to make a program that counts the number of vowels assuming that <code>s</code> is a string that is predefined. But I'm getting an error:</p>
  <blockquote>
  <p>'int' object is not iterable error in python</p>
  </blockquote>