Top Python Interview Questions and Answers (2025)

Prepare for your Python interviews with these top questions and clear, concise answers. This guide covers Python basics, OOP concepts, data structures, libraries, and debugging, ideal for freshers and experienced candidates.

Python Interview Questions and Answers

1. What is Python?
An interpreted, high-level, general-purpose programming language.

2. What are the key features of Python?
Easy-to-read syntax, dynamic typing, interpreted, object-oriented, and extensive libraries.

3. What is PEP 8?
Python Enhancement Proposal 8, a style guide for writing clean and readable Python code.

4. What is the difference between list and tuple?
Lists are mutable; tuples are immutable.

5. What is a dictionary in Python?
An unordered collection of key-value pairs.

6. What is slicing in Python?
Extracting parts of sequences like strings, lists, and tuples.

7. What is a lambda function?
An anonymous function defined with the lambda keyword.

8. What is the difference between deep copy and shallow copy?
Shallow copy copies references; deep copy copies objects recursively.

9. What is the use of self in Python?
Represents the instance of the class in methods.

10. What is init in Python?
A constructor method that initializes object state.

11. What are Python decorators?
Functions that modify the behavior of other functions.

12. What is pickling and unpickling?
Serialization and deserialization of Python objects.

13. What is the difference between range and xrange?
In Python 2, range returns a list; xrange returns an iterator. In Python 3, only range exists.

14. What is a generator in Python?
A function that returns an iterator using the yield statement.

15. What is the use of *args and kwargs?
*args passes variable number of non-keyword arguments; **kwargs passes variable keyword arguments.

16. What is the GIL in Python?
Global Interpreter Lock that allows only one thread to execute at a time.

17. What is the difference between append() and extend()?
append() adds a single element; extend() adds elements from an iterable.

18. What are built-in data types in Python?
int, float, str, list, tuple, dict, set, and bool.

19. What are local and global variables in Python?
Local variables are defined inside functions; global variables are defined outside functions.

20. How do you handle exceptions in Python?
Using try, except, finally blocks.

21. What is the purpose of the pass statement?
A null statement used as a placeholder.

22. What are Python modules and packages?
Modules are .py files; packages are collections of modules.

23. What is recursion in Python?
A function calling itself to solve problems.

24. How do you manage memory in Python?
Using automatic garbage collection.

25. What is the difference between == and is?
== checks value equality; is checks identity.

26. What is list comprehension?
A concise way to create lists using expressions inside brackets.

27. What is the map() function used for?
Applies a function to all items in an iterable.

28. What is filter() used for?
Filters elements of an iterable based on a function.

29. What does the zip() function do?
Combines multiple iterables into tuples.

30. What is the difference between remove(), pop(), and del?
remove() removes a value; pop() removes by index and returns it; del deletes by index or slice.

31. How to install packages in Python?
Using pip: pip install package_name.

32. What is virtualenv?
A tool to create isolated Python environments.

33. What is the use of the with statement?
Simplifies exception handling for resources like files.

34. What are Python iterators?
Objects that can be iterated one element at a time.

35. What is the difference between a class and an object?
Class is a blueprint; object is an instance of the class.

36. What is inheritance in Python?
Allows a class to inherit properties and methods from another class.

37. What is polymorphism in Python?
Ability to take multiple forms with methods.

38. What is encapsulation in Python?
Hiding internal state using private and protected members.

39. What are magic methods in Python?
Special methods with double underscores like init, str, len.

40. How is multithreading handled in Python?
Using the threading module but limited by GIL.

41. What is the difference between multithreading and multiprocessing?
Multithreading runs threads; multiprocessing runs processes for parallelism.

42. What is the purpose of the name variable?
Used to check whether the script is run directly or imported.

43. What are docstrings in Python?
Documentation strings used for documentation within functions, classes, and modules.

44. How do you open a file in Python?
Using the open() function with modes like ‘r’, ‘w’, ‘a’.

45. What is JSON handling in Python?
Using the json module to encode and decode JSON data.

46. What are common Python libraries used in development?
NumPy, Pandas, Matplotlib, Requests, Flask, Django.

47. What is the purpose of the sys module?
Provides access to system-specific parameters and functions.

48. What is exception handling best practice in Python?
Catch specific exceptions and avoid bare except.

49. What is a set in Python?
An unordered collection of unique elements.

50. Why choose Python for development?
Easy syntax, large community support, versatile use cases in data science, web, and automation.

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