Test your knowledge: Python Lists

Review

1. What happens after queue = queue.append("bread")?

   append grows the list in place and hands back None, so the assignment throws the list away and keeps the None. The mutation already happened, to the object the name used to point at.
2. After a = b on two list names, what do the two names share?

   Assignment binds the name to the object the other name already points at, so both names see one list, and a change through either is a change through both. Copying is a separate, deliberate act.
3. What did queue[:2] give the example's archive?

   Slicing produces a new list holding the chosen elements, so the archive kept its two items while the queue it came from kept growing. That is the honest copy, and it is why the lesson reached for a slice when it wanted one.
4. What does queue.pop(0) do?

   pop(0) removes and returns the element at index zero, the front of the queue, so the earliest arrival is the earliest departure. With no argument, pop takes from the end instead, which is a stack, not a queue.
5. What does "bread" in basket ask?

   The in operator asks whether the value equals one of the container's elements, and answers with a boolean. Counting occurrences is a different method's job.