Subset and superset checks in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this subset check?

Consider the following Python code:

set_a = {1, 2, 3, 4}
set_b = {2, 3}

What is the output of set_b.issubset(set_a)?

Python

set_a = {1, 2, 3, 4}
set_b = {2, 3}
print(set_b.issubset(set_a))

A True

B False

C TypeError

D None

💡 Hint

Remember, a subset means all elements of one set are in the other.

set_b contains elements 2 and 3, both of which are in set_a. So set_b is a subset of set_a, and the method returns True.

❓ Predict Output

intermediate

What does this superset check return?

Look at this code:

set_x = {5, 6, 7, 8}
set_y = {6, 7}

What is the output of set_x.issuperset(set_y)?

Python

set_x = {5, 6, 7, 8}
set_y = {6, 7}
print(set_x.issuperset(set_y))

A True

B KeyError

C False

D None

💡 Hint

Superset means the first set contains all elements of the second.

set_x contains 5,6,7,8 which includes all elements of set_y (6,7), so it returns True.

❓ Predict Output

advanced

What is the output of this subset check with an empty set?

Given:

set_m = set()
set_n = {1, 2, 3}

What does set_m.issubset(set_n) print?

Python

set_m = set()
set_n = {1, 2, 3}
print(set_m.issubset(set_n))

A False

B True

C TypeError

D None

💡 Hint

Think about whether an empty set is a subset of any set.

An empty set is considered a subset of every set, so the method returns True.

❓ Predict Output

advanced

What does this superset check return?

Look at this code:

set_a = {1, 2, 3}
not_a_set = [1, 2]

What happens when running set_a.issuperset(not_a_set)?

Python

set_a = {1, 2, 3}
not_a_set = [1, 2]
print(set_a.issuperset(not_a_set))

A AttributeError

B False

C True

D TypeError

💡 Hint

issuperset accepts any iterable, not just sets.

issuperset accepts any iterable argument, so it checks if all elements of the list are in the set. Since 1 and 2 are in set_a, it returns True.

🧠 Conceptual

expert

Which option shows the correct way to check if set A is a strict subset of set B?

You want to check if set A is a subset of set B but not equal to B. Which code snippet does this correctly?

A set_a.issuperset(set_b)

B set_a <= set_b

C set_a.issubset(set_b) and set_a != set_b

D set_a < set_b

💡 Hint

Python has operators for strict subset and subset or equal.

The < operator checks for strict subset (subset but not equal). The <= operator allows equality. Option D is logically correct but less concise. Option D checks superset, which is the opposite.