title: django two digit integer in choice field
body: <p>I have a form that I want to submit date as <code>mm/yyyy</code>.</p>
  
  <pre><code>class Add_Serv(forms.Form):
     month_add = forms.ChoiceField(required=True, choices=['01','02'])
     year_add = forms.ChoiceField(required=True, 
                choices=[(x, x) for x in xrange(date.today().year - 1, date.today().year + 1)])
  </code></pre>
  
  <p>When my month prints out in form, it's only one digit integer <code>1</code> instead of <code>01</code>. It doesn't sound like a big deal but it screws up my date format when handling these dates (and also looks very ugly). Is there any way to keep that zero before the number?</p>