title: Change in Python built in round() function between 2.4 and 2.7
body: <p>Has the built in round() function in Python changed between 2.4 and 2.7?</p>
  
  <p>Python 2.4:</p>
  
  <pre><code>Python 2.4.6 (#1, Feb 12 2009, 14:52:44)
  [GCC 3.4.6 20060404 (Red Hat 3.4.6-8)] on linux2
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; f = 1480.39499999999998181010596454143524169921875
  &gt;&gt;&gt; round(f,2)
  1480.4000000000001
  &gt;&gt;&gt;
  </code></pre>
  
  <p>Python 2.7:</p>
  
  <pre><code>Python 2.7.1 (r271:86832, May 13 2011, 08:14:41)
  [GCC 3.4.6 20060404 (Red Hat 3.4.6-11)] on linux2
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; f = 1480.39499999999998181010596454143524169921875
  &gt;&gt;&gt; round(f, 2)
  1480.39
  &gt;&gt;&gt;
  </code></pre>
  
  <p>Is there anyway to get the Python 2.4 behaviour back?</p>
  
  <p>I'm aware that the right answer is of course to use the decimal arithmetic module. Unfortunately, this probably isn't an option at this point given time limitations.</p>
  
  <p><strong>Update</strong></p>
  
  <p>For context i'm comparing values in two systems, one of which uses a decimal representation and the other a floating point one. This may (or may not) be a legitimate difference between the systems which needs to be checked further, so i'll consult users and deal with it at the "reporting" level, rather than at the point I get the data from the systems.</p>
  
  <p>Thanks for your help!</p>