I was trying to make a cart system in Django and wanted to pass Size and the Quantity of product as <Select>

input in View. My Template have :

<ul class="list-unstyled">
              Select Size:
              <select  name="sizes">
                {% for size in product.sizes.all %}
                <li class="list-item list-inline-item"><option value="{{size.nameSize}}">{{size.nameSize}}</option> </li>
                {% endfor %}
              </select>


          </ul>

This is how it looks :

But when i Submit it using the Add to Cart Button i get error:

This is the code in the view:

def add_item(request,pk):
product = get_object_or_404(Product,pk=pk)
size = request.POST['sizes']
selectsize = Size.objects.get(nameSize=size)
user = request.user
usercart = Cart.objects.get(owner=user)
newitem = CartItems.objects.create(cart = usercart,product=product,size=selectsize) 
items = usercart.cartitems
return render(request,'cart.html',{'cartitems':items})

I am trying to use the name of the size from the Template and compare the size name i have in the database for that product Using:

selectsize = Size.objects.get(nameSize=size)

I was able to get size with name 36 so i wanted to pass the value 36 from the template to the variable size using post.

But i get the error mentioned which i believe is because name for the <select> is common in all the <option>.

If i can either get an alternate way to do that or solve this error both type of solutions are welcomed. *I am not using Django Forms because i don't know how to have django form display like i am displaying my products in cart and on the product page.

ANSWER

I was missing a submit button and was rather using a <a href="{% url 'add_item' product.pk %}>Add To Cart</a>" to submit the form which was not working. Now i replaced it with <button class="btn btn-success" style="margin-top: 10px;" type="submit">Add To Cart New</button> And the form Action is given the link i was trying to go to.

 <form method="post" enctype="multipart/form-data" action="{% url 'add_item' product.pk %}">

A silly mistake on my side.

Thanks for the answers.