Solution
If two variables refer to the same list, a change made through one name also appears through the other. Insertion, deletion, or replacement is not copied; both names point to one object in memory. This can cause unexpected results when you meant to keep an independent copy.
PYTHON
party_list = ["Invite friends", "Buy decorations", "Buy snacks"]
another_list = party_list
another_list.remove("Buy snacks")
print(party_list)
# Output: ['Invite friends', 'Buy decorations']
another_list does not create a new list. After remove(), party_list is also changed. To avoid this, make a copy, for example another_list = party_list.copy(), before modifying.