If statement on a Model.field

Question

hopefully this is clear.

I am trying to put together a view that takes care of what happens when a user places a bid on an active listing on the auction site I am trying to build. I'm doing an if statement to tackle what happens if a user tries to bid on a closed listing but pylint keeps throwing a syntax error on the line that reads:

if auction.status is not 'active':

I have tried:

if auction.status is closed:

if auction.status.closed:

Is it a keyword that I'm missing or parentheses?

models.py

class Listing(models.Model):

    class NewManager(models.Manager):
        def get_queryset(self):
            return super().get_queryset().filter(status='active')

    options = (
        ('active', 'Active'),
        ('closed', 'Closed'),
    )

    title = models.CharField(max_length=64)
    description = models.TextField(max_length=64)
    price = models.DecimalField(max_digits=9, decimal_places=2, validators=[MinValueValidator(0.99)])
    image = models.URLField(max_length=200, blank=True)
    category = models.ForeignKey(Category, on_delete=models.CASCADE, related_name="listings")
    lister = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, default=None, null=True, blank=True)
    status = models.CharField(max_length=10, choices=options, default="active")
    favourites = models.ManyToManyField(User, related_name="favourite", default=None, blank=True)
    objects = models.Manager()
    listingmanager = NewManager()

    def __str__(self): 
        return f"Product: {self.title} \nDescription: {self.description} \nCurrent Price: £{self.price}\nImage: {self.image} \nCategory: {self.category} \nListed by: {self.lister}"


class Bid(models.Model):
    bidder = models.ForeignKey(User, on_delete=models.CASCADE, related_name="bidders")
    item = models.ManyToManyField(Listing, related_name="bid_item", default=None, blank=True)
    price = models.DecimalField
    time = models.TimeField()

views.py

def bidding(request, listing_id):
    bid_item = get_object_or_404(Listing, pk=listing_id)
    bid_item.resolve()
    bidding = Bid.objects.filter(bidder=request.user.filter(listing=listing).first()

    if auction.status not 'active':
        return render(request, "auctions/listingPage.html", {
            'listing': listing,
            'error': 'This auction has closed.'
        })
    
    try:
        bid_amount = request.POST['bid']
        if not bid_amout or float(bid_amount) < listing.price:
            raise(KeyError)
        if not bid:
            bid = Bid()
            bid.item = bid_item
            bid.bidder = request.user
            bid.price = bid_amount
            bid.time = timezone.now()
    except(KeyError):
        return render(request, 'auctions/listingPage.html', {
            'listing': listing,
            'error': 'Invalid bid amount.'
        })
    else:
        bid.save()
        return HttpResponseRedirect(reverse('listing', args=()))

Answer 1

in python the is not operator isn't the same as the not equals != operator

also in your code it says

if auction.status not 'active':

which doesn't have the "is" in it

try doing this to see if it helps

if auction.status != 'active':