Difference and symmetric difference in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of set difference operation

What is the output of this Python code?

Python

a = {1, 2, 3, 4}
b = {3, 4, 5, 6}
result = a - b
print(result)

A {1, 2, 3, 4, 5, 6}

B {3, 4}

C {5, 6}

D {1, 2}

💡 Hint

Remember, set difference returns elements in the first set not in the second.

The difference a - b returns elements in a that are not in b, which are 1 and 2.

❓ Predict Output

intermediate

Output of symmetric difference operation

What does this code print?

Python

x = {10, 20, 30}
y = {20, 40, 50}
print(x ^ y)

A {10, 30, 40, 50}

B {10, 20, 30, 40, 50}

C {20}

D {40, 50}

💡 Hint

Symmetric difference returns elements in either set but not both.

The symmetric difference excludes 20 because it is in both sets, leaving 10, 30, 40, and 50.

🧠 Conceptual

advanced

Understanding difference with empty set

What is the result of the difference operation when subtracting an empty set from a non-empty set?

A The original non-empty set

B An empty set

C A set with all elements doubled

D A set with elements removed randomly

💡 Hint

Think about what elements are removed when subtracting nothing.

Subtracting an empty set removes no elements, so the original set remains unchanged.

❓ Predict Output

advanced

Result of chained symmetric difference

What is the output of this code?

Python

a = {1, 2, 3}
b = {2, 3, 4}
c = {3, 4, 5}
result = a ^ b ^ c
print(result)

A {1, 4, 5}

B {1, 2, 5}

C {1, 3, 5}

D {2, 3, 4, 5}

💡 Hint

Symmetric difference is associative; think step-by-step.

First a ^ b = {1, 4}, then {1, 4} ^ c = {1, 3, 5}.

🔧 Debug

expert

Identify the error in set difference code

Which option will cause an error when run?

Python

s1 = {1, 2, 3}
s2 = [2, 3, 4]
result = s1 - s2
print(result)

A s1.difference(s2)

B s1 - s2

C s1 - set(s2)

D s1.symmetric_difference(s2)

💡 Hint

Check the types used in the difference operation.

Subtracting a list from a set with '-' operator raises a TypeError.