title: Regular Expressions: Equivalent of \d for any letter in Python?
body: <p>Is there any character equivalent of \d for letters in Regular Expressions? For instance if trying to find a numerical pattern of digits in the form <code>"(111) 111-1111"</code> this code works:</p>
  
  <pre><code>pattern = re.compile(r'(\(\d\d\d) (\d\d\d\-\d\d\d)')
  </code></pre>
  
  <p>But how would you rewrite this code if the pattern digits are letters instead of numbers? In other words, how can the above code be changed so that it can match lettters of the pattern <code>"(abc) efg-hijk"</code>?  </p>