pythonLogic errorEasy

Boolean evaluation on custom empty container treats object as false

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What it should do

is_valid_cart_container(items) returns True if cart was successfully initialized as an object, even if items is empty. Example: is_valid_cart_container([]) → True.

What happens instead

is_valid_cart_container([]) returns False because an empty collection evaluates to false in truthiness checks.

class CustomCart:
    def __init__(self, items):
        self.items = items
    def __len__(self):
        return len(self.items)

def is_valid_cart_container(items):
    cart = CustomCart(items)
    if cart:
        return True
    return False

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

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This bug belongs to the logic errors pattern

The wrong operator, an inverted condition, a formula the right way round but backwards.

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class CustomCart: def __init__(self, items): self.items = items def __len__(self): return len(self.items) def is_valid_cart_container(items): cart = CustomCart(items) if cart: return True return False

Boolean evaluation on custom empty container treats object as false

What it should do

What happens instead

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Boolean evaluation on custom empty container treats object as false

What it should do

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