title: Check presence of vowels in a string
body: <p>I need to check whether a vowel is present in a word. If it is, an operation should be carried out on the word say <code>op(word)</code>. I want to avoid a for loop because I thought of this:</p>
  
  <pre><code>for char in word:
      if char in 'aeiou':
  #confused here... 
  </code></pre>
  
  <p>Please, recommend a method that is low in cost when it comes to execution time. Also, help me correct the above approach too.</p>