Add Cart to Order

I want to make a website with Python-Django, in my case i want to add Item in Cart to Order information. Order model contain User information and OrderItem model contain the Item refer to Order information.

and after that i want to clear the Cart

model.py

class Order(models.Model):
    full_name = models.CharField(max_length=50)
    address = models.CharField(max_length=50)
    city = models.CharField(max_length=15)
    state = models.CharField(max_length=15)
    postcode = models.CharField(max_length=10)
    phone = models.CharField(max_length=15)
    email = models.EmailField()

class OrderItem(models.Model):
    order = models.ForeignKey(Order, related_name='item', on_delete=models.CASCADE)
    product = models.ForeignKey(Product, related_name='order_items', on_delete=models.CASCADE)
    price = models.DecimalField(max_digits=10, decimal_places=0)
    quantity = models.PositiveIntegerField(default=1)

admin.py

from .models import Member, Product, Image, Category, Order, OrderItem

class OrderItemInline(admin.TabularInline):
    model = OrderItem
    raw_id_fields = ['product']

class OrderAdmin(admin.ModelAdmin):
    list_display = ['id', 'full_name', 'address', 'city', 'state', 'postcode', 'phone', 'email']
    inlines = [OrderItemInline]

admin.site.register(Order, OrderAdmin)

form.py

class OrderCreateForm(forms.Form):
    full_name = forms.CharField(widget=forms.TextInput(attrs={'class':'form-control'}))
    address = forms.CharField(widget=forms.TextInput(attrs={'class':'form-control'}))
    city = forms.CharField(widget=forms.TextInput(attrs={'class':'form-control'}))
    state = forms.CharField(widget=forms.TextInput(attrs={'class':'form-control'}))
    postcode = forms.CharField(widget=forms.NumberInput(attrs={'class':'form-control'}), required=True)
    phone = forms.CharField(widget=forms.NumberInput(attrs={'class':'form-control'}), required=True)
    email = forms.EmailField(widget=forms.EmailInput(attrs={'class':'form-control'}))

views.py

from .models import Member, Product, Image, User, OrderItem
from .forms import *

def checkout(request):
    cart_items = request.session

    # Create an empty cart object if it does not exist yet 
    if not cart_items.has_key("cart"):
        cart_items["cart"] = {}

    item_ids = cart_items["cart"].keys()
    products = Product.objects.filter(pk__in=item_ids)

    cart_total = 0
    for item in products:
        cart_item = cart_items["cart"].get(str(item.id))
        cart_total = (item.price * cart_item.get("quantity")) + cart_total

    form = OrderCreateForm(request.POST)

    if request.method == 'POST':
        if form.is_valid():
            order = Order.objects.create(
                full_name = form.cleaned_data['full_name'],
                address = form.cleaned_data['address'],
                city = form.cleaned_data['city'],
                state = form.cleaned_data['state'],
                postcode = form.cleaned_data['postcode'],
                phone = form.cleaned_data['phone'],
                email = form.cleaned_data['email']
                )

            for item in products:
                orderitem = OrderItem.objects.create(
                    order = order,
                    product = item['product'],
                    price = item['price]',
                    quantity = item['quantity']
                    )

            cart_items.clear()
            order.save()
            orderitem.save()

            # return HttpResponse(result)
        return render(request,'ecommerce/products/')
    else:
        # return HttpResponse(result)
        return render(request, Helpers.get_url('checkout.html'), {'cart_session_items': cart_items["cart"], 'cart_db_items': products, 'cart_total': float("%0.2f" % (cart_total)), 'currency': EcommerceConfig.currency, 'form': OrderCreateForm()})

and this is my error

this is how admin.py look

i'm sorry for my bad English, please kindly ask me if the information not clear Thanks