Django admin：使用多个选择复选框的选项渲染模型字段

Question

我想将模型字段渲染为复选框，以便我将选项预定义为元组列表，我该怎么做？

class Car(models.Model):
    groups = models.CharField(max_length=100,
                              blank=False)

class CarAdmin(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        super(CarForm, self).__init__(*args, **kwargs)
        self.fields['groups'].widget = forms.CheckboxSelectMultiple(choices=CARS_ALLOWED)