Python tuple MCQ questions with answers

Answer: B

len() counts the top-level items: 1, 2, the tuple (3, 4) and the list [5, 6]. The items inside the nested tuple and list are not counted separately.

Answer: A

The right side y, x is packed into the tuple (7, 3) before anything is assigned, then unpacked into x and y. That is why the swap needs no temporary variable.

Answer: C

+ joins two tuples into (1, 2, 3), and * 2 repeats its items, giving a new flat tuple of six items. It does not multiply each number.

Answer: D

count(6) returns how many times 6 appears, which is 3. index(3) returns the position of the first 3, and positions start at 0, so it is 4.

Answer: B

tuple() makes one item from each element of an iterable, and iterating over a string gives its characters. For a one-item tuple holding the whole string, write ('abc',).

Answer: B, TypeError: 'tuple' object does not support item assignment

Tuples are immutable, so assigning to an index raises TypeError. To change an item, build a new tuple, for example ('Sun',) + days[1:].

Answer: B, Once created, a tuple cannot have items added, removed or replaced

Tuples are immutable: no method or assignment changes their items. They can mix types freely, and the commas, not the parentheses, make a tuple: u = 1, 2 is a tuple too.

Answer: A

The trailing comma makes a one-item tuple. ('red') is a string inside grouping parentheses, tuple('red') splits the string into three characters, and square brackets make a list.

Answer: C

The starred name collects every value the other names do not take, here 2, 3 and 4. A starred target is always a list, even when the value being unpacked is a tuple.

Answer: D

A tuple cannot change which objects it holds, but the list inside it is still mutable. t[1].append(4) changes that list in place, so printing the tuple shows the longer list.

Answer: A

Tuples compare item by item from the left, and the first difference decides. In (1, 2, 3) < (1, 3) the second items give 2 < 3, so the result is True and length does not matter. In the second comparison 2 > 1 decides at once.

Answer: B

Slicing a tuple always returns a tuple, so t[1:2] is the one-item tuple (20,), printed with its comma. Indexing with t[1] returns the item itself, 20.

Answer: C

Inside square brackets, 1, 2 is a tuple, so points[1, 2] looks up the key (1, 2). Tuples can be dictionary keys because they are immutable and hashable.

Answer: C, ValueError: too many values to unpack (expected 2)

Unpacking needs exactly as many names as values unless one name is starred. Three values into two names raises ValueError; a, *b = (1, 2, 3) would work.

Answer: C, A tuple of immutable items is hashable; a list is mutable and never hashable

Dictionaries find keys by their hash, which must never change. A tuple of immutable items can be hashed; a list can change, so hash([1, 2]) raises TypeError and lists cannot be keys.

Answer: D

Tuples have no sort() or sorted() method because they cannot change. The built-in sorted() accepts a tuple but always returns a list, so wrapping it in tuple() gives a sorted tuple.

Answer: D

t[1] += [4] runs in two steps: the list's += extends it in place, then Python tries to store the result back into t[1]. That store fails with TypeError, but the list has already changed.

Answer: A

tail takes the only value, so nothing is left for head. A starred target can collect zero values, and it is then an empty list, never None or a tuple.

Answer: A, TypeError: unhashable type: 'list'

A tuple is hashable only when every item in it is hashable. This tuple holds a list, so hashing it for the dictionary key raises TypeError. (1, (2, 3)) would work as a key.

Answer: D, A generator object that produces 0, 1 and 4 when iterated

Parentheses around a comprehension make a generator expression, not a tuple: Python has no tuple comprehension. Wrap it in tuple(...) to get (0, 1, 4).