Getting MultiValueDictKeyError while checking if a field is empty-CodePudding

I have a regsitration form where a user chooses a plan. I am trying to check that if the field is empty a message should be displayed. The field name is plan. The code is below

if password1==password2:
            if CustomUser.objects.filter(email=email).exists():
                messages.info(request, 'User with same email already exists')
                return redirect('register')
            
            elif plan is None:
                messages.info(request, 'Please select a plan')
                return redirect('register') 
            else:
                user=CustomUser.objects.create_user(full_name=full_name.upper(),age=age, phone_no=phone_no, address=address, plan=plan, email=email.lower(), password=password1)
                user.is_active = False
                user.save()
                
                usr_otp = random.randint(100000, 999999)
                UserOtp.objects.create(user = user, otp = usr_otp)
                mess =  f"Hello, {user.full_name},\n Please enter the otp to validate your email and activate your account. \nYour OTP is {usr_otp} .\n Thanks!"
                
                return render(request, 'register.html', {'otp': True, 'user': user})
                # return redirect('login')

I have tried multiple ways to check whether the plan field is empty or not such as

elif plan == ' '

elif not plan

elif plan is None

elif request.POST['plan'] == ' '

for all these I am getting only one error

MultiValueDictKeyError at /account/register
'plan'
Request Method: POST
Request URL:    http://127.0.0.1:8000/account/register
Django Version: 3.2.8
Exception Type: MultiValueDictKeyError
Exception Value:    
'plan'
Exception Location: C:\Users\rickb\Envs\virenv\lib\site-packages\django\utils\datastructures.py, line 78, in __getitem__
Python Executable:  C:\Users\rickb\Envs\virenv\Scripts\python.exe
Python Version: 3.9.7
Python Path:    
['C:\\Users\\rickb\\Envs\\virenv\\jgs',
 'C:\\Users\\rickb\\AppData\\Local\\Programs\\Python\\Python39\\python39.zip',
 'C:\\Users\\rickb\\AppData\\Local\\Programs\\Python\\Python39\\DLLs',
 'C:\\Users\\rickb\\AppData\\Local\\Programs\\Python\\Python39\\lib',
 'C:\\Users\\rickb\\AppData\\Local\\Programs\\Python\\Python39',
 'C:\\Users\\rickb\\Envs\\virenv',
 'C:\\Users\\rickb\\Envs\\virenv\\lib\\site-packages']
Server time:    Mon, 06 Dec 2021 23:30:33  0530

I don't understand why I am getting this, Please correct me what I am doing wrong and how to check that the plan field is empty.

The plan field in the html is a radio button that passes a value

CodePudding user response：

Try this instead:

elif request.POST.get('plan') == ' '

In python square brackets give error if there is no entry whereas get function returns None..

CodePudding user response：

If the plan field is empty, the key 'plan' won't exist in request.POST. So to verify if this field is empty you can do this

elif request.POST.get('plan') is None:

Since get will return None if the plan field is empty.