title: Python string format a float, how to truncate instead of rounding
body: <p>Is there a format option such that</p>
  
  <pre><code>&gt;&gt;&gt; '%.1(format)'%2.85
  </code></pre>
  
  <p>gives '2.8'?</p>
  
  <p>In Python 2.7, 'f' format rounds to nearest</p>
  
  <pre><code>&gt;&gt;&gt; "{:.0f}".format(2.85)
  '3'
  &gt;&gt;&gt; "%.0f"%2.85
  '3'
  &gt;&gt;&gt; "%.1f"%2.85
  '2.9'
  &gt;&gt;&gt; "%i"%2.85
  '2'
  </code></pre>