I dont know why but you can fix it explicitly using Decimal. http://docs.python.org/library/decimal.html#module-decimal
2012/3/5 Francisco <[email protected]>: > Hi everyone. I just came across a weird behavior and I'm wondering if it's > some kind of bug or just my fault. > > I have a model for a product like this: > > db.define_table('products', > Field('name',length=128, notnull=True), > Field('sale_price',type='decimal(14,4)',default=0, notnull=True)) > > Now when the user adds a product to the cart I'm storing the row for the > product in a dictionary in the session like this: > > session.cart[product.id] = product > > finally the view that displays it lets you pick among several payment > options and based on the option it multiplies the price by another number > like this: > > {{=session.cart[id].sale_price * session.payment_factor}} > > Both sale price and payment factor are store in DB as decimal(14,4). The > first time the code is run the view executes correctly. But when you add > another product to the cart, or modify any other thing that requires a > reload or repost of the page I get an error like this: > > TypeError: unsupported operand type(s) for *: 'float' and 'Decimal' > > > So what is happening is that after the first time my variable which is store > in the session and that should be treated like a Decimal is being returned > as a float. This is happening in the development environment with SQLite, I > have not tested this yet under MySQL. I think it is caused by the fact that > SQLite stores decimals as float, buy I wonder why does the first time it is > transformed to Decimal, and then just used as a float? And I wonder if I > must manually converted them to Decimal every time I use this variables. > > Hope someone can help. -- Carlos J. Costa Cientista da Computação Esp. Gestão em Telecom EL MELECH NEEMAN! אָמֵן
