Python Full-Stack Interview Questions 1-5 (core Python features, Python 2 vs 3 differences, memory management, built-in data types, and mutability)

1. What are Python's key features?

Python is widely appreciated for being clear, expressive, and flexible. It helps developers focus on solving problems rather than struggling with syntax. Whether you're building APIs, server-side logic, data pipelines, or integrating with frontend applications, Python provides a clean and consistent development experience.

# Example: clean and readable logic
numbers = [1, 2, 3, 4]
squared = [n*n for n in numbers]
print(squared)  # [1, 4, 9, 16]

2. Difference between Python 2 and Python 3

Python 3 is the modern and actively supported version of the language. Python 2 has reached end-of-life, meaning it no longer receives updates or security fixes. In professional settings and interviews, always assume Python 3 unless stated otherwise.

# Python 3 examples
print("Hello", "World", sep=", ")

print(5 / 2)   # 2.5 (true division)
print(5 // 2)  # 2   (floor division)

3. Explain Python memory management

Python automatically manages memory through a combination of reference counting and garbage collection. This means most of the time you don't need to manually free memory, but understanding the model helps when optimizing large applications.

import gc

# Force a full garbage collection cycle (not usually needed)
gc.collect()

4. What are Python data types?

Python provides a variety of built-in data types used to store and organize data. Choosing the appropriate type can make your code more efficient and easier to reason about.

user = {"name": "Aisha", "role": "Admin"}
print(user["name"])  # Aisha

5. Difference between mutable and immutable objects

Mutability describes whether an object's value can change after it is created. Understanding this helps prevent unintended side effects and bugs.

# Mutable
items = [1, 2, 3]
items.append(4)

# Immutable
name = "John"
name = name + " Doe"  # new string created