Python 如何处理view.py文件中的django模型表单错误？

这是我的forms.py文件。我们可以从forms.py中的clean方法验证表单数据

from django import forms
from django.core.exceptions import ValidationError


    class ContactForm(forms.Form):
        # Everything as before.
        ...
    
        def clean_recipients(self):
            data = self.cleaned_data['recipients']
            if "fred@example.com" not in data:
                raise ValidationError("You have forgotten about Fred!")
    
            # Always return a value to use as the new cleaned data, even if
            # this method didn't change it.

但是我想验证view.py中的一些数据。我们可以这样做吗？在view.py文件中

class Test(View) :
    def get(self,request):
      #Get logic 
   def post(self,request):
      form = ContactForm(request.POST or None)
      if form.is_valid():
          num = form.cleaned_data['num']
          
          if '123' in num:
               form.add_error('num','Not valid')
          else:
               form.save()
              
      return render(request,self.template_name,{'form':form})

使用消息处理view.py而不是forms.py中的表单错误的方法是什么

from django import forms
from django.core.exceptions import ValidationError


    class ContactForm(forms.Form):
        # Everything as before.
        ...
    
        def clean_recipients(self):
            data = self.cleaned_data['recipients']
            if "fred@example.com" not in data:
                raise ValidationError("You have forgotten about Fred!")
    
            # Always return a value to use as the new cleaned data, even if
            # this method didn't change it.

views.py

from django.contrib import messages
class Test(View) :
    def post(self,request):
        form = ContactForm(request.POST or None)
        if form.is_valid():
            num = form.cleaned_data['num']

            if '123' in num:
                messages.error(request, 'Not valid')
            else:
                form.save()

        return render(request,self.template_name,{'form':form})

模板

{% if messages %}
    {% for message in messages %}
        <p>{{ message }}</p>
    {% endfor %}
{% endif %}

{{num}}

然后在模板中使用变量

{{num}}

---

您可以使用消息，也可以将表单错误作为上下文传递给模板。