Shopping cart quantity not updating - python-3.6

Question

I have a basic shopping cart. I thought it was working but I have since discovered that even though it runs error free it is not doing one thing I thought it should and I am having trouble resolving the issue.
If I instantiate an item a second time, like this:
item1 = Item(1, "Cucumbers", 1., 1, 'kg')
item2 = Item(2, "Tissues", 2., 2, 'dozen')
item3 = Item(3, "Tomatoes", 3., 5, 'pound')
# item4 = Item(4, "Toothpaste", 1., 5, 'box')
item4 = Item(4, "Cucumbers", 1., 2, 'kg')
What I want is for the quantity of cucumbers in item 1 to increase to '3'
and for item 4 to be auto-deleted.
I thought this was doing what I intended, but it's not:
elif k == 'name':
total_qty = v.qty + item.qty
if total_qty:
v.qty = total_qty
continue
self.remove_item(k)
else:
v[k] = item[k]
The code runs error free but I end up with two separate instances of cucumber.
Full code:
class Item(object):
def __init__(self, unq_id, name, price, qty, measure):
self.unq_id = unq_id
self.product_name = name
self.price = price
self.qty = qty
self.measure = measure
class Cart(object):
def __init__(self):
self.content = dict()
def __format__(self, format_type):
if format_type == 'short':
return ', '.join(item.product_name for item in self.content.values())
elif format_type == 'long':
return '\n'.join(f'\t\t{item.qty:2} {item.measure:7} {item.product_name:12} # '
f'${item.price:1.2f} ... ${item.qty * item.price:1.2f}'
for item in self.content.values())
def add(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).items():
if k == 'unq_id':
continue
elif k == 'name':
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.items()])
def get_num_items(self):
return sum([v.qty for _, v in self.content.items()])
def remove_item(self, key):
self.content.pop(key)
if __name__ == '__main__':
item1 = Item(1, "Cucumbers", 1., 1, 'kg')
item2 = Item(2, "Tissues", 2., 2, 'dozen')
item3 = Item(3, "Tomatoes", 3., 5, 'pound')
# item4 = Item(4, "Toothpaste", 1., 5, 'box')
item4 = Item(4, "Cucumbers", 1., 2, 'kg')
cart = Cart()
cart.add(item1)
cart.add(item2)
cart.add(item3)
cart.add(item4)
print("Your cart contains: {0:short}".format(cart))
# cart.remove_item(1)
print()
print("Your cart contains: \n {0:long}".format(cart))
print()
print("The total number of items in your cart is: ", cart.get_num_items())
print()
print("The total cost of the items in your cart is: ", cart.get_total())
print()
cart.remove_item(3)
print("Your cart contains: {0:short}".format(cart))
print()
print("Your cart contains: \n {0:long}".format(cart))
print()
print("The total number of items in your cart is: ", cart.get_num_items())
print()
print("The total cost of the items in your cart is: ", cart.get_total())

Answer 1

The fix is:
def add(self, item):
if item.unq_id not in self.content:
self.content.update({item.unq_id: item})
return
else:
self.content[item.unq_id].qty = self.content[item.unq_id].qty + item.qty