Builtins Easy

What does this code print?

print(len([1, 2, 3, 4]))

• 0

• 3

• 4

• TypeError

Answer

len returns the number of items in a container; the list has 4 elements.

What does this code print?

print(sorted([3, 1, 2]))

• [1, 2, 3]

• [3, 2, 1]

• None

• [3, 1, 2]

Answer

sorted returns a new list in ascending order; it never mutates its argument and never returns None.

What does this code print?

print(sum([1, 2, 3]))

• [1, 2, 3]

• 123

• 0

• 6

Answer

sum adds the items of an iterable starting from 0: 1 + 2 + 3 == 6.

What does this code print?

print(bool([]))

• True

• False

• []

• None

Answer

An empty list is falsy, so bool([]) is False. Empty containers are always falsy.

What does this code print?

print(list("ab"))

• ['ab']

• ['a', 'b']

• 'ab'

• [97, 98]

Answer

list on a string iterates its characters, producing a one-character string per element.

What does this code print?

print(max([4, 2, 9, 1]))

• 1

• 4

• 9

• 16

Answer

max returns the largest item of the iterable, which is 9.

What does this code print?

print(min([4, 2, 9, 1]))

• 1

• 2

• 4

• 9

Answer

min returns the smallest item of the iterable, which is 1.

What does this code print?

print(list(range(3)))

• [1, 2, 3]

• [0, 1, 2]

• [0, 1, 2, 3]

• [3]

Answer

range(3) yields 0, 1, 2 — it starts at 0 and stops before the given stop value.

What does this code print?

print(int("100"))

• 4

• "100"

• 1.0

• 100

Answer

int parses a decimal string into an integer, giving 100.

What does this code print?

print(len({"a": 1, "b": 2}))

• 4

• 2

• 1

• 3

Answer

len of a dict counts its keys; there are 2.

What does this code print?

print(list(enumerate(["x", "y"])))

• [('x', 0), ('y', 1)]

• [(1, 'x'), (2, 'y')]

• [(0, 'x'), (1, 'y')]

• ['x', 'y']

Answer

enumerate pairs each item with a counter starting at 0, yielding (index, value) tuples.

What does this code print?

print(bool(0))

• True

• False

• 0

• None

Answer

The number 0 is falsy, so bool(0) is False.

What does this code print?

print(sorted("dbca"))

• ['a', 'b', 'c', 'd']

• 'abcd'

• ['d', 'c', 'b', 'a']

• ['dbca']

Answer

sorted always returns a list, even when given a string: it iterates the characters and sorts them.

What does this code print?

print(tuple([1, 2]))

• [1, 2]

• (1, 2)

• {1, 2}

• (1, 2,)

Answer

tuple builds an immutable sequence from the iterable, printed as (1, 2).

What does this code print?

print(set([1, 1, 2, 2]))

• [1, 1, 2, 2]

• {1, 1, 2, 2}

• (1, 2)

• {1, 2}

Answer

A set holds only unique elements, so the duplicates collapse to {1, 2}.

What does this code print?

print(float("3.5"))

• 3

• "3.5"

• 3.5

• ValueError

Answer

float parses a numeric string, including a decimal point, into a floating-point number.

What does this code print?

print(any([False, True, False]))

• True

• False

• 1

• None

Answer

any is True if at least one element is truthy; here one True is enough.

What does this code print?

print(all([True, True, False]))

• True

• False

• 0

• None

Answer

all is True only if every element is truthy; the single False makes it False.

What does this code print?

print(sum([]))

• None

• []

• TypeError

• 0

Answer

sum of an empty iterable returns its start value, which defaults to 0.

What does this code print?

print(divmod(17, 5))

• (2, 3)

• 3.4

• (3, 2)

• (3.4, 0)

Answer

divmod(a, b) returns (a // b, a % b) — the quotient 3 and the remainder 2.