python - 干掉类似的表单类

Question

我有一个带有简单验证码的 python/django 应用程序。根据某种算法出现简单的验证码。

有两个几乎相同的构造函数。区别仅在于继承。如何避免代码重复？

class PostCaptchaForm(PostForm):
    captcha = CaptchaField()

    def __init__(self, *args, **kwargs):
        self.request = kwargs['request']
        del kwargs['request']

        super(PostCaptchaForm, self).__init__(*args, **kwargs)

    def clean(self):
        cleaned_data = super(PostCaptchaForm, self).clean()

        success = self.is_valid()
        utils.update_captcha_access(self.request, success)

        if success:
            return cleaned_data
        else:
            raise forms.ValidationError("captcha validation failed")


class ThreadCaptchaForm(ThreadForm):
    captcha = CaptchaField()  

    def __init__(self, *args, **kwargs):
        self.request = kwargs.pop('request')

        super(ThreadCaptchaForm, self).__init__(*args, **kwargs)

    def clean(self):
        cleaned_data = super(ThreadCaptchaForm, self).clean()

        success = self.is_valid()
        utils.update_captcha_access(self.request, success)

        if success:
            return cleaned_data
        else:
            raise forms.ValidationError("captcha validation failed")

Answer 1

我会使用多重继承，将基本验证码表单作为 mixin，与 ThreadForm 或 PostForm 一起使用

class CaptchaFormBase(forms.Form):  # or forms.ModelForm, if appropriate

    captcha = CaptchaField()

    def __init__(self, *args, **kwargs):
        self.request = kwargs.pop('request')  
        # this is the same as assigning to self request then deleting the key

        super(CaptchaFormBase, self).__init__(*args, **kwargs)


    def clean(self):
        cleaned_data = super(CaptchaFormBase, self).clean()

        success = self.is_valid()
        utils.update_captcha_access(self.request, success)

        if not success:
            # this will put things in non_field_errors, you may want to put it in self.errors['captcha']
            raise forms.ValidationError("Captcha validation failed")

        # always make it easy to see that you're returning cleaned_data
        return self.cleaned_data


class PostCaptchaForm(PostForm, CaptchaFormBase):
    pass


class ThreadCaptchaForm(ThreadForm, CaptchaFormBase):
    pass