title: Django tuple/choices field is not translating
body: <p>I have an Integer ModelField with a set of choices.</p>
  
  <p><code>field = models.IntegerField(choices=CHOICES_CONSTANT)</code></p>
  
  <p>This <code>CHOICES_CONSTANT</code> is defined in another file and imported</p>
  
  <pre><code>CHOICES_CONSTANT = (
      (0, _('One')),
      (1, _('Two')),
      ...
  )
  </code></pre>
  
  <p>The <code>_</code> is from <code>from django.utils.translation import ugettext_lazy as _</code> as the model field requires you to use lazy translations.</p>
  
  <p>I also import the <code>CHOICES_CONSTANT</code> into other files (such as reports) where in a report I might say <code>str(dict(CHOICE_CONSTANT)[object.field]) if object.field else ''</code>.</p>
  
  <p><strong>This</strong> <code>str(dict(CHOICES_CONSTANT)[object.field]) if object.field else ''</code> does not get translated. In fact, if I just <code>print(CHOICES_CONSTANT)</code> it immediately evaluates to the default language (English). </p>
  
  <p>In other places I would do <code>object.get_field_display()</code> and that also does not translate.</p>
  
  <p>Any help would be much appreciated.</p>