Django: ModelForm中Meta的fields成员有什么作用?

看了源代码和官方文档,但还是不明白fields到底改变了什么?

django/forms/models.py:

'fields' is an optional list of field names. If provided, only the named fields will be included in the returned dict.

class MyForm(forms.ModelForm):
    realname = forms.CharField()
    phone = forms.CharField()

    class Meta:
        model = MyUser
        fields = ('phone',)

form = MyForm()
# 照样会输出realname
form.as_table()

---

fields 是把MyUser 中的字段拿过来，你用什么就拿什么 比如MyUser 中有realname , phone 两个字段，在MyForm 中可以不用在定义了，直接写在 fields = ('realname','phone',)就可以了