title: How to take value from UserProfile if it exist in another modelForm as default value
body: <p>I have UerProfile defined and need to take phone data for MyForm</p>
  
  <pre><code> class UserProfile(models.Model):
       ...
       phone = models.CharField(max_length=20, blank=True)
  
  
   class CustomModel(models.Model):
       ...
       phone = models.CharField(max_length=20)
  
  
   class MyForm(forms.ModelForm):
  
       class Meta:
           model = CustomModel
           exclude = ['some_fields_but_not_phone',]
  </code></pre>
  
  <p>Now I need to take phone data from UserProfile if it is set, to be prepopulated value in {{ form.phone }} field. Then user can change it or leave it as is when he submit form.</p>