Python Developer Interview Questions and Answers

Types of Questions to Expect in a Python Developer Interview

• Core Fundamentals: "What is the difference between a list and a tuple, and when would you use one over the other?"
• Memory Management: "How does Python handle memory management and garbage collection? Explain the role of the Global Interpreter Lock (GIL)."
• Data Structures: "How would you use a dictionary to count the frequency of words in a large text file?"
• Object-Oriented Programming (OOP): "Explain the difference between class methods and static methods. How does inheritance work in Python?"
• Libraries & Frameworks: Questions about your experience with NumPy, Pandas, Django, or Flask, depending on the specific role.

What the Interviewer Will Expect

• Readability (PEP 8): Do you follow the standard Python style guidelines? They want to see clean variable names and proper indentation.
• Efficiency: Can you optimize your code? They will look for your ability to reduce time complexity ($O(n)$) using built-in functions.
• Testing Mindset: Do you write unit tests for your code using frameworks like pytest or unittest?
• Debugging Skills: When code fails, can you explain your process for finding the bug using logging or a debugger?
• Breadth of Knowledge: Do you understand how Python interacts with databases, APIs, and the local file system?

Tips on Getting Ready

1. Practice on a Whiteboard: Many technical interviews require you to write code without the help of an IDE (no auto-complete). Practice writing common algorithms on paper.
2. Master List Comprehensions: Being able to turn a 4-line for loop into a single, readable line of code shows you truly understand the language.
3. Review the "Built-ins": Know your way around functions like map(), filter(), zip(), and enumerate().
4. Understand Decorators: Be ready to explain—and write—a decorator. It is a common "senior-level" question to test your depth of knowledge.
5. Explain Your Logic Out Loud: During the coding test, talk through your thought process. Interviewers care more about how you solve a problem than if you get the syntax 100% perfect on the first try.