Python Interview Questions: 40 Essential Questions for Senior Roles

Most beginners think Python strings are easy… Until they get stuck in interviews 😅 Here are the string concepts that actually matter 👇 🧠 Indexing & Slicing → Access any character like a pro → Example: text[1:5] ⚡ Negative Indexing → Read from the end → text[-1] gives last character 📏 String Length → len(text) is your best friend 🔧 Important Methods → upper(), lower(), title() → Clean and format data instantly ➕ Concatenation → "Hello" + " World" = "Hello World" 🔍 Substring Check → "Py" in text → True → Useful in real projects 🔗 Split & Join → Convert strings ↔ lists easily 💡 Pro Tip: Strings are immutable (you can’t change them directly) 🚀 If you're learning Python, master this once → it will help in: • Coding rounds • Projects • Data Science Save this for revision 🔖 Follow Harsh Vardhan Dubey for more simple coding breakdowns 💻 #Python #LearnPython #Programming #Coding #PythonBasics #100DaysOfCode #Developers #TechSkills #Upskill

Master Python Interviews with 50 Advanced Questions & Answers They revise syntax… But struggle when questions go deeper. So I created something practical “Python Interview Questions & Answers – 50 Advanced Topics” This is not basic stuff. It covers the kind of questions that actually test your thinking: • Real-world problem solving. • Advanced Python concepts. • Interview-level scenarios. • Clear, structured answers. If you're aiming for better opportunities, this is the level you should prepare at. I personally compiled this to make preparation more focused and less overwhelming. Comment “PYTHON” and I’ll share it with you. #Python #PythonInterview #Coding #SoftwareEngineering #BackendDeveloper #LearnPython #TechCareers #PythonDeveloper

Today I worked on a common interview problem: finding duplicates in a list efficiently. ⸻ 🔹 Question: Find duplicates in a list Problem: Write a Python function to return all duplicate elements from a list. ⸻ ✅ Approach 1: Using Sets (Efficient – O(n)) def find_duplicates(nums): seen = set() duplicates = set() for num in nums: if num in seen: duplicates.add(num) else: seen.add(num) return list(duplicates) print(find_duplicates([1, 2, 3, 2, 4, 1, 5])) # Output: [1, 2] ⸻ ✅ Approach 2: Using Dictionary Count def find_duplicates(nums): count = {} for num in nums: count[num] = count.get(num, 0) + 1 return [num for num, freq in count.items() if freq > 1] print(find_duplicates([1, 2, 3, 2, 4, 1, 5])) # Output: [1, 2] 💡 Key Learnings: • Using sets helps achieve O(n) time complexity • Dictionaries are useful for frequency counting • Learned how to handle duplicates efficiently without nested loops #Python Day 6 #Learning # Developer # Leetcode # Small improvement 👍 #Self Growing

🐍 Python Trick — Did you get it right? b = a doesn't copy the list. It points to the SAME object in memory. So when b changes... a changes too. 🤯 This one gotcha has caused more bugs than most people admit. 💡 Always use b = a.copy() or b = a[:] when you need a true copy. Drop a ✅ if you got it right or a ❌ if it surprised you! Follow for more Python tricks, AI/LLM tips & SQE insights every week. 🔔 #Python #PythonTricks #SoftwareEngineering #SQE #Coding #100DaysOfCode #AIEngineering #TechLinkedIn #PythonDeveloper

Struggling with subarray problems? This one pattern can solve most of them 👇 If you’re preparing for coding interviews or improving your problem-solving skills, the Prefix Sum technique is a must-know pattern. 💡 What is Prefix Sum? It’s a way to store the cumulative sum of elements so that you can quickly calculate the sum of any subarray in constant time. 👉 Example: For array [1, 2, 3, 4] Prefix sum becomes → [1, 3, 6, 10] 🎯 Why use it? . Reduces time complexity from O(n²) → O(n) . Helps solve problems like: - Subarray sum = k - Longest subarray with given sum - Count of subarrays 🧠 Core Idea: Instead of recalculating sums again and again: sum(i to j) = prefix[j] - prefix[i-1] 🔥 Power Boost with HashMap Combine prefix sum with a hashmap to: - Track previously seen sums - Solve complex problems in one pass ⚡ Key Patterns to Remember: - currentSum += nums[i] - Check currentSum - k - Store sum in hashmap - For longest → store first occurrence - For count → store frequency 💬 Learning Tip: Don’t just memorize the code — understand why we store sums and how we use them. 📌 Prefix Sum is not just a trick — it’s a pattern that appears again and again in interviews. Keep practicing. Keep improving. 💪 #DSA #CodingInterview #Programming #Python #SoftwareEngineering #Learning #100DaysOfCode

Python interview prep in 25 pages. Not bad. We came across this doc from Bosscoder Academy, covers everything from basic data types to Scikit-learn, with code snippets for each question. Honestly the kind of thing you bookmark and forget about until the night before an interview. Topics include OOP, string handling, lambda functions, list comprehension, Pandas, NumPy, Seaborn, Matplotlib, and ML basics with Scikit-learn. Pretty solid for anyone getting started or brushing up. Full credit goes to Bosscoder Academy for putting this together. We're sharing it because we think it's useful, not because we made it. If you know the original author by name, drop it in the comments and we'll update. Save this one. You'll need it eventually. What Python concept tripped you up the most during your last interview, and how did you end up explaining it? #Python #InterviewPrep #DataScience #MachineLearning

I learned the hard way: details matter. Edge cases can kill you. I'd nailed the overall strategy, but those pesky edge cases cost me. 32 iterations later, I finally got it. The interviewer's hint stuck: "O(1)? Think divide and conquer." Swap those halves, then refine. Reverse Bits, a LeetCode problem, is about reversing bits of a 32-bit unsigned integer. Naive approach: 32 iterations, shifting and ORing. But there's a better way - swap halves, then 8-bit blocks, then 4, 2, 1. Only five steps. You're swapping larger blocks first, refining as you go. Each step doubles the size of properly ordered regions. It's tough. This is a standard bit-manipulation interview question, testing block operations thinking. I had to redo a lot. In Python, use a mask - & 0xFFFFFFFF. Python integers are arbitrary precision, so without masking, you get more than 32 bits. In C/Java, it's all about unsigned right shift. This pattern doesn't often extend to other problems, but it's one drill worth doing - for that "can you do O(1)?" follow-up. Once the bit trick clicks, the O(1) follow-up stops feeling like magic. Take a closer look and start practicing - it'll make you better off in the next coding interview. #LeetCode #OpenToWork #CodingInterview #InterviewPrep

💻 Python Interview Question: What is the difference between shallow copy and deep copy? 👉 Shallow copy: Copies reference of nested objects 👉 Deep copy: Creates a completely new copy (recursive) Understanding these concepts can save you from tricky bugs. 🚀 Keep learning beyond basics. #Python #InterviewPrep #Coding #Developers #Learning

Most people think Python is "slow" because it's dynamic. I used to think that too. Then I started working on Pyrefly. Static analysis is essentially a "spell-checker" for code. At Meta's scale, we can't wait 20 minutes for a test to run. We need to catch bugs the millisecond they are typed. Working on a Rust-powered engine that processes 1.8 million lines of code per second has taught me one thing: Efficiency isn't a luxury; it's a requirement. I’m learning how to bridge the gap between Python’s flexibility and Rust’s safety. It’s challenging, it’s frustrating, and it’s the most fun I’ve ever had. #RustLang #Python #StaticAnalysis #SystemsEngineering

Built a small side project this weekend. A Python script that pulls the full transcript from any YouTube video. No API key. No login. Paste the URL, get a .txt file with every word in seconds, no matter how long the video length is. (I tried Gemini first to extract the transcript, because both Youtube and Gemini are owned by Google and gemini have Youtube data, but it failed because of the video length) Then I took a 2-hour podcast transcript and extracted every tip and framework the guest mentioned, turned it into a full YouTube content strategy doc in English. 30 pages. 8 steps using Claude. Honestly didn't expect it to come out that clean. If you are into content, this might help. Those who want this python script, can reach me out. I'm documenting whatever I build, small or big. If you do the same, let's connect. #SideProject #Python #ContentStrategy