title: Counting each letter's frequency in a string
body: <p>This is a question from pyschools.</p>
  
  <p>I did get it right, but I'm guessing that there would be a simpler method. Is this the simplest way to do this?</p>
  
  <pre class="lang-py prettyprint-override"><code>def countLetters(word):
      letterdict={}
      for letter in word:
          letterdict[letter] = 0
      for letter in word:
          letterdict[letter] += 1
      return letterdict
  </code></pre>
  
  <p>This should look something like this:</p>
  
  <pre><code>&gt;&gt;&gt; countLetters('google')
  {'e': 1, 'g': 2, 'l': 1, 'o': 2}
  </code></pre>