What is the issue with the following code? ```python def add_to_inventory(item, inventory=[]): inventory.append(item) return inventory print(add_to_inventory("apple")) print(add_to_inventory("banana")) ```

The function uses a mutable default argument (inventory=[]). In Python, default argument values are evaluated only once when the function is defined, not each time it is called. As a result, the same list object is reused across all calls. The first call appends "apple" to the list, and the second call appends "banana" to the same list, so both prints output ['apple', 'banana']. This can lead to unexpected behavior if callers expect a fresh list each time.

To fix it, use None as the default and create a new list inside the function:

def add_to_inventory(item, inventory=None):
    if inventory is None:
        inventory = []
    inventory.append(item)
    return inventory

Now each call gets its own list, producing ['apple'] and ['banana'] respectively.