Python Coding challenge - Day 1190| What is the output of the following Python Code?

 

Code Explanation:

🔹 1. Importing deque

from collections import deque

✅ Explanation:

deque stands for Double Ended Queue.

It is available in Python's collections module.

It allows insertion and deletion from both the left and right ends efficiently.

Visual representation:

Left End                 Right End

← [ deque ] →

🔹 2. Creating a Deque

d = deque([10, 20, 30])

✅ Explanation:

A deque object is created with three elements.

Current deque:

deque([10, 20, 30])

Visual:

Left                  Right

10 ← 20 ← 30

Current state:

d

↓

[10, 20, 30]

🔹 3. Using appendleft()

d.appendleft(5)

✅ Explanation:

appendleft() inserts a new element at the beginning (left side) of the deque.

Before:

[10, 20, 30]

Insert:

5

After:

[5, 10, 20, 30]

Visual:

Left

5 ← 10 ← 20 ← 30

Right

Current state:

d

↓

[5, 10, 20, 30]

🔹 4. Using append()

d.append(40)

✅ Explanation:

append() adds a new element at the end (right side) of the deque.

Before:

[5, 10, 20, 30]

Insert:

40

After:

[5, 10, 20, 30, 40]

Visual:

Left

5 ← 10 ← 20 ← 30 ← 40

Right

Current state:

d

↓

[5, 10, 20, 30, 40]

🔹 5. Using pop()

d.pop()

✅ Explanation:

pop() removes the last (rightmost) element from the deque.

Current deque:

[5, 10, 20, 30, 40]

Removed element:

40

Remaining deque:

[5, 10, 20, 30]

Visual:

Before

5 ← 10 ← 20 ← 30 ← 40

❌ Remove

After

5 ← 10 ← 20 ← 30

🔹 6. Final Deque State

After all operations:

deque([5, 10, 20, 30])

Current state:

d

↓

[5, 10, 20, 30]

🔹 7. Converting Deque to List

list(d)

✅ Explanation:

list() converts the deque into a normal Python list.

Before:

deque([5, 10, 20, 30])

After:

[5, 10, 20, 30]

🔹 8. Printing the Result

print(list(d))

✅ Explanation:

Prints the final list.

Output:

[5, 10, 20, 30]

🎯 Final Output

[5, 10, 20, 30]

BOOK: 100 Python Programs for Beginner with explanation