如何使用小部件在Django中向表单添加属性？

Question

我正在尝试让占位符显示表单字段，但我的表单字段出错了。有什么想法吗？我有以下课程：

class EditField(forms.CharField):
    def __init__(self, *args, **kwargs):
        super(EditField, self).__init__(*args, **kwargs)
        self.widget = forms.Textarea(attrs={'id':'editor'})
        self.label  = _('content')

class EditField_typeA(EditField):
    def __init__(self, *args, **kwargs):
        super(EditField_typeA, self).__init__(*args, **kwargs)
    def clean(self, value):
        if not (len(re.sub('[ ]{2,}', ' ', value)) < settings.FORM_MIN):
            raise forms.ValidationError(_('content must be %s') % settings.FORM_MIN)
        return value

class FinalForm(forms.Form):
    foo  = FooField()
    bar  = BarField()
    text   = EditField_typeA()

    def __init__(self, data=None, user=None, *args, **kwargs):
        super(FinalForm, self).__init__(data, *args, **kwargs)

        ## THIS IS THE PART THAT ISN'T WORKING    
        self.fields['text'].widget.attrs['placeholder'] = 'Fill this in' 

        if int(user.reputation) < settings.CAPTCHA_IF_REP_LESS_THAN and not (user.is_superuser or user.is_staff):
            spam_fields = call_all_handlers('create_anti_spam_field')
            if spam_fields:
                spam_fields = dict(spam_fields)
                for name, field in spam_fields.items():
                    self.fields[name] = field

                self._anti_spam_fields = spam_fields.keys()
            else:
                self._anti_spam_fields = []

我猜我错误地使用了widget，或者在错误的地方。找不到小部件文档的正确部分来解释我做错了什么。