Python Interview Questions with with Answers

Certainly! Here are 100

Python interview questions and answers in brief:

Basics

1. What is Python?

• Python is an interpreted high-level programming language known for its readability and versatility.

1. How is Python interpreted?

• Line by line, Python code is executed, and the interpreter converts it into intermediate code, which is then executed by the Python Virtual Machine (PVM).

1. Explain the difference between Python 2 and Python 3.

• Python 3 is the most recent version, with improvements and changes that are incompatible with Python 2.

1. What are the key features of Python?

• The key characteristics are readability, simplicity, and versatility. It supports the paradigms of object-oriented, imperative, and functional programming.

1. What is PEP 8?

• PEP 8 is the Python Enhancement Proposal that provides style guide recommendations for writing code in Python.

1. How do you comment in Python?

• Single-line comments start with #, and multi-line comments are enclosed in triple quotes (''' or """).

1. Explain Python’s GIL (Global Interpreter Lock).

• GIL is a mutex that protects access to Python objects, preventing multiple threads from executing Python bytecode simultaneously.

1. What is a docstring?

• A docstring is a string literal used for documenting Python modules, classes, functions, or methods.

1. What is the purpose of the pass statement in Python?

• pass is a no-operation statement used as a placeholder where syntactically some code is required but no action is desired.

1. What is the purpose of the __init__ method in Python?
   • __init__ is a special method used for initializing object attributes when an instance of the class is created.

Data Types

11. Explain mutable and immutable types in Python.
    • Mutable types can be modified after creation (e.g., lists), while immutable types cannot (e.g., tuples).
12. What is the difference between list and tuple in Python?
    • Lists are mutable, and tuples are immutable. Lists use square brackets ([]), while tuples use parentheses (()).
13. Explain the difference between == and is in Python.
    • == compares values, and is compares object identity (whether they reference the same object in memory).
14. How do you convert a string to an integer in Python?
    • Use the int() function, e.g., int("42").
15. What is the purpose of the ord() and chr() functions in Python?
    • ord() returns the Unicode code point of a character, and chr() returns a character from a Unicode code point.
16. Explain the concept of truthy and falsy values in Python.
    • Values that evaluate to True in a Boolean context are truthy, and those evaluating to False are falsy.
17. How do you swap the values of two variables in Python without using a temporary variable?
    • Use tuple unpacking, e.g., a, b = b, a.
18. What is the purpose of the None keyword in Python?
    • None is a special constant representing the absence of a value or a null value.
19. How do you concatenate two lists in Python?
    • Use the + operator or the extend() method.
20. Explain the purpose of the *args and **kwargs in function definitions.
    • *args allows a function to accept any number of positional arguments, and **kwargs allows any number of keyword arguments.

Control Flow

21. Explain the purpose of if __name__ == "__main__": in Python scripts.
    • It allows a script to be both importable as a module and executable as a standalone program.
22. How do you iterate over a dictionary in Python?
    • Use for key, value in my_dict.items().
23. What is the purpose of the break and continue statements in Python?
    • break terminates the loop, and continue skips the rest of the code inside the loop for the current iteration.
24. Explain the use of try, except, else, and finally in Python exception handling.
    • try contains the code that might raise an exception, except handles the exception, else executes if no exception occurs, and finally executes regardless of an exception.
25. How do you use a list comprehension in Python?
    • [expression for item in iterable if condition].
26. What is the purpose of the pass statement in a loop?
    • It is a no-operation statement, often used as a placeholder where syntactically some code is required.
27. Explain the concept of a generator in Python.
    • A generator is a special type of iterator that yields values lazily using the yield keyword.
28. How can you create an infinite loop in Python?
    • Use while True:.
29. What is the purpose of the range() function in Python?
    • It generates a sequence of numbers and is often used for iterating over a sequence.
30. Explain the use of the enumerate() function in Python.
    • It adds a counter to an iterable, returning tuples with the counter and the iterable’s elements.

Functions

31. What is a lambda function in Python?
    • A lambda function is an anonymous function defined using the lambda keyword.
32. What is the difference between return and yield in a function?
    • return ends the function and returns a value, while yield pauses the function, allowing it to be resumed later.
33. Explain the concept of closures in Python.
    • Closures allow a nested function to capture and remember the values of the variables in the outer (enclosing) function’s scope.
34. How do you define a default value for a function parameter in Python?
    • Define the parameter with a default value, e.g., def my_function(param=value):.
35. What is the purpose of the **kwargs parameter in a function?
    • It allows a function to accept any number of keyword arguments.
36. How can you call a function with a variable number of arguments?
    • Use *args to pass a variable number of positional arguments.
37. Explain the concept of recursion in Python.
    • Recursion is when a function calls itself. It is essential to have a base case to prevent infinite recursion.
38. What is the purpose of the __init__ method in a class?
    • It initializes the attributes of an object when an instance is created.
39. What is the purpose of the staticmethod and classmethod decorators in Python?
    • staticmethod defines a static method, and classmethod defines a method that belongs