Python Developer Interview Questions

Preparing for job interviews is one of the most important tasks when you seek work as a Python Developer. While you may already have stock answers to questions like, "Where do you see yourself in five years," a Python development role typically requires specific answers to questions about Python.

You can find many online lists of possible interview questions for Python professionals. Some will emphasize development, some will emphasize data science, and others will be basic programming questions. For Python development or data science roles, you will likely have to solve coding problems or explain terms rather than just answering general questions.

What to Expect in a Python Developer Interview

Python Developer interview formats can vary from company to company and position to position. Smaller companies may have a single person interview you, while a large corporation is more likely to conduct multiple rounds of interviews. For instance, a Web Developer might do a first-round technical interview, a second-round skills-based interview, and a third-round professional interview.

Technical interviews might require you to display proficiency in writing, testing, or debugging Python programs. Skills-based interviews typically test an applicant's knowledge in frameworks, libraries, variables, or other areas of Python. And professional interviews can be more general, focusing on standard questions about your accomplishments, work style, or which aspects of Python development you enjoy most.

Top Interview Questions for Python Developers

Python Developer job candidates may need to practice answering common questions to prepare for a job interview. In addition to studying, they may also need to review their project portfolio, review Python-related subjects like Django and Flask, and prepare answers for standard interview questions about previous jobs or preferred communication methods.

While a complete list of potential interview questions is beyond the scope of this article, the following are examples of some common questions and suggestions for how to answer them.

What does Python do?

Python professionals already know the answer to this question, and you may wonder why an interviewer would ask it. The reasoning behind this question is twofold: to ensure your answer focuses on Python development, and to see whether you expand on the answer beyond basics.

How to answer

Depending on whether the interview is a first, second, or third round, your interviewer may not be as versed in Python as yourself. Consider your audience as you explain that Python is an object-oriented language. You might add some features or benefits, but keep your answer concise.

Why did you choose to specialize in Python?

This type of question falls within the professional interview category, although an experienced Developer or Product Manager might ask it, too. The question behind the question is what you like about Python or what appeals to you.

How to answer

Consider this question one of your best opportunities. Briefly and honestly answer it, whether you focus on Python's popularity and versatility or the high demand in your chosen field. Avoid lengthy explanations about personal reasons and focus on how your strengths match well with Python.

How does Python manage memory?

One of the most common questions for entry-level Python Developers, interviewers ask it to gauge your understanding of Python basics.

How to answer

This question requires a straightforward answer. Python, not the user, controls memory management. It stores objects and data structures in a private heap with raw memory and object-specific allocators. Again depending on your interviewer, you should not get too far into the weeds on basic technical questions like this one.

What are the differences between tuples and lists in Python?

This question also helps assess a candidate's understanding of Python fundamentals. The reasoning behind it is to see how you explain the differences among classes of Python data structures. Your interviewer might also ask you to compare and contrast sets or dictionaries in Python.

How to answer

The basic answer is that lists can be changed while tuples cannot. You can also note the difference in syntax between the two. If prompted, you might expand on both, but again the simple answer is best—especially if your interviewer is not a fellow development pro.

What are the main differences between Python and Java?

Like other fundamental Python development questions, the reasoning behind the question is to test your knowledge. While you might not be an expert in Java, basic Python proficiency typically includes some of the main differences between Python and other popular programming languages.

How to answer

Again, how you answer depends on your interviewer, but you should still keep it concise. A few key differences in categories like syntax and speed should answer the question. 

Name three distinct Python features.

Most basic Python interviews include some variation on this question. Here the difference will be based on whether you are interviewing for an entry-level, intermediate, or advanced position. The reasoning behind this question also depends on the wording.

How to answer

If you are interviewing for an entry-level Python development role, this question may be, "Name three key Python features." In this case, you may be able to offer answers highlighting Python's portability or ease of use.

For intermediate or advanced roles, your interviewer may want you to discuss features that distinguish Python from other languages. Here, you might want to emphasize something more specific. For example, you can mention that Python requires fewer lines of code than Java, or that its automated garbage collection makes it memory-efficient.

Name three built-in Python modules.

Modules help users organize content. Python modules contain variables and functions, and the many built-in modules in Python are among its essential features.

Your interviewer may ask you to name built-in Python modules and some of the most-used modules. This question falls into the fundamentals category, and by the time you interview for a Python development position, you will have more than three at your fingertips.

How to answer

The Python standard library has over 200 modules, so it may be difficult, if not impossible, to remember them all. Type help ('modules') in Python, and you can see the entire list. Keep your answer simple by choosing from among key built-in modules, like:

• collections
• math
• os
• random
• sys

What was your most successful portfolio project?

The reasoning behind this question is simple: it helps demonstrate the value you bring to the position. While many interviews don't include questions of this type, focusing on technical and skills-based problems, this is more of a professional interview question.

How to answer

Here is one of your best chances to shine. If the project offers something unique, concentrate on that aspect. If you had to overcome some challenges and it will benefit you to mention them, do so. You may be able to display your creativity and problem-solving skills in your answer.

These samples represent a tiny fraction of the many questions an interviewer can ask a Python Developer candidate. Master all the fundamentals and any relevant advanced questions, and your preparation and hard work can pay off in the long run. 

Learn the Skills to Become a Python Developer at Noble Desktop

To become a Python Developer, everyone needs a range of skills and knowledge. Most people start with basics, like functions, variables, and the principles of object-oriented programming (OOP). Progressing to a development role also can include additional server-side languages like React (JSX), machine learning algorithms, and object-relational mapping (ORM).

Noble Desktop offers a range of online and in-person Python classes and bootcamps for development, data science and analytics, FinTech, and cybersecurity. Instructors with practical expertise teach these programs, which feature small class sizes to ensure individual attention. Each graduate receives a certificate of completion and can even retake the course for up to one year at no additional charge.

Many Python novices review some free online resources to prepare for one of these courses. Noble Desktop’s Learn Hub includes a comprehensive guide to learning Python for development or data-centered roles. Here you can check out free on-demand courses and tutorials on topics like exchanging Excel for Python and making a Twitter bot with Python. 

If you’re new to Python training, you might want to start with an immersive course like Noble’s Python Programming Bootcamp. However, you can also save by taking this bootcamp as part of their immersive Python Developer Certificate. This program provides Python fundamentals before taking participants through in-demand tools like Django REST, Git, and SQL. Check course listings for more details, including prerequisite information.