Here is a fully functional shopping cart as you want:
class Item(object):
def __init__(self, unq_id, name, price, qty):
self.unq_id = unq_id
self.product_name = name
self.price = price
self.qty = qty
class Cart(object):
def __init__(self):
self.content = dict()
def update(self, item):
if item.unq_id not in self.content:
self.content.update({item.unq_id: item})
return
for k, v in self.content.get(item.unq_id).iteritems():
if k == 'unq_id':
continue
elif k == 'qty':
total_qty = v.qty + item.qty
if total_qty:
v.qty = total_qty
continue
self.remove_item(k)
else:
v[k] = item[k]
def get_total(self):
return sum([v.price * v.qty for _, v in self.content.iteritems()])
def get_num_items(self):
return sum([v.qty for _, v in self.content.iteritems()])
def remove_item(self, key):
self.content.pop(key)
if __name__ == '__main__':
item1 = Item(1, "Banana", 1., 1)
item2 = Item(2, "Eggs", 1., 2)
item3 = Item(3, "Donut", 1., 5)
cart = Cart()
cart.update(item1)
cart.update(item2)
cart.update(item3)
print "You have %i items in your cart for a total of $%.02f" % (cart.get_num_items(), cart.get_total())
cart.remove_item(1)
print "You have %i items in your cart for a total of $%.02f" % (cart.get_num_items(), cart.get_total())
Here is the output:
You have 8 items in your cart for a total of $8.00
You have 7 items in your cart for a total of $7.00
I hope this helps you.