Django 表单向导和 recaptcha

我使用以下命令进行了验证码集成Django 片段 http://www.djangosnippets.org/snippets/1653/

settings.py

    RECAPTCHA_PUBLIC_KEY = '<your public key>'
    RECAPTCHA_PRIVATE_KEY = '<your private key>'


#widgets.py

    from django import forms
    from django.utils.safestring import mark_safe
    from django.conf import settings
    from recaptcha import captcha

    class ReCaptcha(forms.widgets.Widget):
    recaptcha_challenge_name = 'recaptcha_challenge_field'
    recaptcha_response_name = 'recaptcha_response_field'

    def render(self, name, value, attrs=None):
        return mark_safe(u'%s' % captcha.displayhtml(settings.RECAPTCHA_PUBLIC_KEY))

    def value_from_datadict(self, data, files, name):
        return [data.get(self.recaptcha_challenge_name, None), 
        data.get(self.recaptcha_response_name, None)]


#fields.py

    from django.conf import settings
    from django import forms
    from django.utils.encoding import smart_unicode
    from django.utils.translation import ugettext_lazy as _

    from marcofucci_utils.widgets import ReCaptcha
    from recaptcha import captcha

    class ReCaptchaField(forms.CharField):
    default_error_messages = {
        'captcha_invalid': _(u'Invalid captcha')
    }

    def __init__(self, *args, **kwargs):
        self.widget = ReCaptcha
        self.required = True
        super(ReCaptchaField, self).__init__(*args, **kwargs)

    def clean(self, values):
        super(ReCaptchaField, self).clean(values[1])
        recaptcha_challenge_value = smart_unicode(values[0])
        recaptcha_response_value = smart_unicode(values[1])
        check_captcha = captcha.submit(recaptcha_challenge_value, 
        recaptcha_response_value, settings.RECAPTCHA_PRIVATE_KEY, {})
        if not check_captcha.is_valid:
        raise forms.util.ValidationError(self.error_messages['captcha_invalid'])
        return values[0]


#forms.py

    class RegistrationForm(forms.Form):
    ...
    recaptcha = marcofucci_fields.ReCaptchaField()
    ...

但是我在 django 表单向导中定义了表单，并且它在字段上调用 ​​clean 方法两次，即使验证码包含在最后一个表单中。

如下：

    from registration.forms import RegistrationWizard,RegistrationForm,ProfileForm

    url(r'^register/$',
        RegistrationWizard([RegistrationForm,ProfileForm]),
        name='register_wizard'),

我该如何规避这种情况。为什么需要在最后一个表单上调用 clean 两次？

如果表单已绑定，则在渲染时它将始终调用 clean （即使您不调用 form.is_valid ）。