Python Interview Questions

Python is the most popular language for data science, backend development, and automation roles. These interview questions cover the core language features that interviewers test — from mutable vs. immutable types and the GIL to advanced patterns like decorators and metaclasses. Each answer goes beyond surface-level definitions to explain the why behind each concept.

8 questions • 5 categories • Updated March 2026

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Core Language

Entry-Level 5 min

Mutable vs Immutable Types in Python — Complete Guide

What is the difference between mutable and immutable types in Python? Why does it matter?
Mid-Level 5 min

List Comprehensions vs Generators in Python

What is the difference between a list comprehension and a generator expression? When would you use each?
Entry-Level 4 min

*args and **kwargs in Python — Flexible Function Arguments

What are *args and **kwargs? How and when do you use them?

Advanced Patterns

Mid-Level 6 min

Python Decorators — How They Work and How to Write Them

How do decorators work in Python? Can you write one from scratch?
Mid-Level 5 min

Python Context Managers — with Statement and Custom Implementations

What are context managers in Python? How do you create a custom one?

Concurrency

Senior 7 min

Python GIL Explained — What It Is and How to Work Around It

What is the GIL in Python? How does it affect multithreading and what are the workarounds?

OOP

Mid-Level 6 min

Python Dunder Methods — Making Custom Classes Pythonic

What are dunder methods in Python? Which ones are most important to implement?

Tooling

Entry-Level 4 min

Python Virtual Environments — venv, pip, and Dependency Management

What is a virtual environment in Python and why should you use one?