title: Enforce the use of 32-bit python
body: <p>I am having some trouble triggering the 32-bit python for my macports python2.7</p>
  
  <pre><code>calvins-MacBook ttys003 Tue Nov 01 01:04:23 |~|
  calvin$ arch -arch x86_64 python
  Python 2.7.2 (default, Oct 31 2011, 20:10:35) 
  [GCC 4.2.1 Compatible Apple Clang 3.0 (tags/Apple/clang-211.10.1)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import platform; platform.architecture()
  ('64bit', '')
  &gt;&gt;&gt; exit()
  calvins-MacBook ttys003 Tue Nov 01 01:04:49 |~|
  calvin$ arch -arch i386 python
  Python 2.7.2 (default, Oct 31 2011, 20:10:35) 
  [GCC 4.2.1 Compatible Apple Clang 3.0 (tags/Apple/clang-211.10.1)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import platform; platform.architecture()
  ('64bit', '')
  &gt;&gt;&gt; 
  </code></pre>
  
  <p>How should I go about triggering the use of 32-bit python?</p>