Python Coding Challenge - Question with Answer (ID 230726)

 

Explanation:

🔹 Line 1: Create a Set

s = {1}

Python creates a set containing one element.

Current set:

s = {1}

Memory:

s

│

▼

{1}

📌 A set is:

Unordered

Mutable

Stores only unique values

🔹 Line 2: Call print()

print(s.pop(), s)

Before printing, Python first evaluates:

s.pop()

🔹 Step 1: Execute pop()

s.pop()

pop() removes one element from the set and returns it.

Since the set contains only one element:

{1}

Python removes:

1

Returned value:

1

Now the set becomes:

set()

which is an empty set.

Memory after pop():

Before

{1}

↓

pop()

↓

{}

🔹 Why Does Python Show set() Instead of {}?

Many beginners expect:

{}

❌ That's incorrect.

In Python:

{}

creates an empty dictionary, not an empty set.

Example:

print(type({}))

Output:

<class 'dict'>

To create an empty set, Python uses:

set()

Example:

print(type(set()))

Output:

<class 'set'>

🔹 Step 2: Evaluate s

After pop(), the variable s now refers to:

set()

Current value:

set()

🔹 Step 3: Execute print()

Now Python has two values:

First:

1

Second:

set()

So it executes:

print(1, set())

Output:

1 set()

Book: Mathematics with Python Solving Problems and Visualizing Concepts