title: str performance in python
body: <p>While profiling a piece of python code (<code>python 2.6</code> up to <code>3.2</code>), I discovered that the
  <code>str</code> method to convert an object (in my case an integer) to a string is almost an order of magnitude slower than using string formatting.</p>
  
  <p>Here is the benchmark</p>
  
  <pre><code>&gt;&gt;&gt; from timeit import Timer
  &gt;&gt;&gt; Timer('str(100000)').timeit()
  0.3145311339386332
  &gt;&gt;&gt; Timer('"%s"%100000').timeit()
  0.03803517023435887
  </code></pre>
  
  <p>Does anyone know why this is the case?
  Am I missing something?</p>