How to return full_name in Django models.ForeignKey(User)?

Question

Django

Hello, tell me how to return the full full_name in Django models.ForeignKey(User) ?
There is a model:

class Master(models.Model):
   master = models.ForeignKey(User, on_delete=models.CASCADE)

The field indicates only the login, how to return the full name and surname of the user

Answer 1

class MasterChoiceField(forms.ModelChoiceField):
     def label_from_instance(self, obj):
         return obj.get_full_name()


class MasterAdmin(admin.ModelAdmin):
    ...

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        if db_field.name == 'master':
            return MasterChoiceField(queryset=User.objects.all())
        return super().formfield_for_foreignkey(db_field, request, **kwargs)