PCEP Data Structures 5

Question 1

What is the output of `a = [1, 2]; b = a; b.append(3); print(a)`?

Accepted Answer

[1, 2, 3]

Answer

Both `a` and `b` reference the same list object, so mutating `b` also changes `a`.

Question 2

What is the correct way to delete a key from a dictionary?

Accepted Answer

del dict['key']

Answer

The `del` statement with a key subscript removes that key from the dictionary.

Question 3

What is the output of `print((1, 2) * 2)`?

Accepted Answer

(1, 2, 1, 2)

Answer

Multiplying a tuple by an integer repeats its contents in a new tuple.

Question 4

Which method returns and removes an arbitrary element from a set?

Accepted Answer

pop()

Answer

`set.pop()` removes and returns an arbitrary element from the set.

Question 5

What is the result of `list({'a': 1, 'b': 2})`?

Accepted Answer

['a', 'b']

Answer

Iterating over a dictionary (or converting it with `list()`) yields its keys.

(PCEP) Certified Entry-Level Python Programmer Practice Test