title: Prepopulate Django (non-Model) Form
body: <p>I'm trying to prepopulate the data in my django form based on some information, but NOT using ModelForm, so I can't just set the instance.</p>
  
  <p>This seems like it should be really easy, but for some reason I can't find any documentation telling me how to do this.  This is my form:</p>
  
  <pre><code>class MyForm(forms.Form):
    charfield1 = forms.CharField(max_length=3)
    charfield2 = forms.CharField(max_length=3)
    choicefield = forms.ModelChoiceField(MyModel.objects.all())
  </code></pre>
  
  <p>I tried just doing:</p>
  
  <pre><code>form = MyForm()
  form.charfield1 = "foo"
  form.charfield2 = "bar"
  # a model choice field
  form.choicefield = MyModel.objects.get(id=3)
  </code></pre>
  
  <p>which does not work.  </p>