title: Count function Python
body: <p>I want to make a function that does the same thing as count, 
  without using count.
  Something like this:</p>
  
  <pre><code>&gt;&gt;&gt; count('mama ma emu a ema ma mamu', 'ma ')
  4
  &gt;&gt;&gt; count('mama ma emu a ema ma mamu', 'am')
  2
  </code></pre>
  
  <p>How could I acheive this?</p>