Django: ModelForm中Meta的fields成员有什么作用?

Question

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()

Answer 1

他就是指定哪些field需要显示到form,因为许多时候根据model创建form,但是form并不需要model中的所有field, 而这个fields选项就可以指定model中的哪些field是form需要的