List mutation and retrieval

Efficiently remove and obtain the last element of a list, supporting LIFO behavior.

Data structures: using a list as a stack where you need to pop the top element; Algorithm implementation: depth‑first search backtracking requiring removal of the last visited node; Undo feature: reverting the most recent action by popping it from a history list

Any Python code using lists as stacks, algorithms like depth-first search, parsing, etc.

result = container.pop()

... = ... .pop()

result: variable name to store popped item; container: list (or any sequence supporting pop).

• list.append()
• list.pop(index)
• collections.deque.pop()

• Using del container[-1] to remove without returning
• or container[-1] to peek.

Assuming pop() returns the list itself, forgetting that it modifies the list, using pop on empty list raises IndexError.

list.pop(i) removes at arbitrary index; deque.pop() from right side; list.remove(value) removes by value.

Coming from languages where pop returns the container (e.g., some stack APIs), expecting the list to be unchanged.

• list.append
• list.pop(index)
• list.remove
• deque.pop
• deque.popleft

pop() is O(1) for the end; pop(i) is O(n). Raises IndexError if list empty; use try/except or check length.

Provides constant-time removal of the last element, enabling efficient stack implementations.

Think of popping the top of a stack of plates.

Use pop() for efficient LIFO removal; remember it modifies the list in place and raises IndexError on empty list.

Use collections.deque for O(1) pops from both ends: d = deque(); d.pop(); d.popleft()