Subset and superset checks in Python - Step-by-Step Execution

Concept Flow - Subset and superset checks

Start with two sets A and B

↓

Check if A is subset of B?

↓

Print True

↓

Check if B is superset of A?

↓

Print True

↓

End

We start with two sets. We check if A is a subset of B, then if B is a superset of A, printing True or False accordingly.

Execution Sample

Python

A = {1, 2}
B = {1, 2, 3}
print(A.issubset(B))
print(B.issuperset(A))

This code checks if A is a subset of B and if B is a superset of A, printing the results.

Execution Table

Step	Operation	Evaluation	Result	Output
1	Define A	A = {1, 2}	{1, 2}
2	Define B	B = {1, 2, 3}	{1, 2, 3}
3	Check A.issubset(B)	Are all elements of A in B?	True
4	Print result of A.issubset(B)	Print True		True
5	Check B.issuperset(A)	Does B contain all elements of A?	True
6	Print result of B.issuperset(A)	Print True		True
7	End	No more operations

💡 All checks done, program ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
A	undefined	{1, 2}	{1, 2}	{1, 2}
B	undefined	undefined	{1, 2, 3}	{1, 2, 3}

Key Moments - 2 Insights

Why does A.issubset(B) return True even though B has an extra element?

Because subset means all elements of A are in B, extra elements in B do not matter (see execution_table step 3).

Is superset just the opposite of subset?

Yes, superset means the set contains all elements of the other set (see execution_table step 5).

Visual Quiz - 3 Questions

Look at the execution table, what is the output at step 4?

A True

B False

C Error

D None

💡 Hint

Check the Output column at step 4 in the execution_table.

At which step does the program check if B is a superset of A?

A Step 3

B Step 2

C Step 5

D Step 6

💡 Hint

Look at the Operation column for the superset check in the execution_table.

If A was {1, 4} instead of {1, 2}, what would A.issubset(B) return?

A True

B False

C Error

D Depends on B

💡 Hint

Refer to the definition of subset in the key_moments and execution_table step 3.

Concept Snapshot

Subset and superset checks in Python:
- Use A.issubset(B) to check if all elements of A are in B.
- Use B.issuperset(A) to check if B contains all elements of A.
- Both return True or False.
- Extra elements in the superset do not affect the result.
- Syntax: set1.issubset(set2), set1.issuperset(set2).

Full Transcript

We start with two sets A and B. We define A as {1, 2} and B as {1, 2, 3}. Then we check if A is a subset of B by verifying if all elements of A are in B. This returns True because 1 and 2 are in B. We print True. Next, we check if B is a superset of A by verifying if B contains all elements of A. This also returns True. We print True. The program ends after these checks.