title: Iterate through class members in order of their declaration
body: <p>I got this problem writing a little GUI lib that maps classes to simple table views. Every class member of a certain type = column, and order of columns is important. But...</p>
  
  <pre><code>class Person(object):
  
      name = None
      date_of_birth = None
      nationality = None
      gender = None
      address = None
      comment = None
  
  
  for member in Person.__dict__.iteritems():
      if not member[1]:
          print member[0]
  </code></pre>
  
  <p>output:</p>
  
  <pre><code>comment
  date_of_birth
  name
  address
  gender
  nationality
  ...
  </code></pre>
  
  <p>ugh, the oder got all mixed up...desired output:</p>
  
  <pre><code>name
  date_of_birth
  nationality
  gender
  address
  comment
  </code></pre>
  
  <p>Is there a way to do it without maintaining additional <code>OrderedDict()</code> of columns?</p>