Top 10 interview questions on Python with answers

Embarking on a Python interview can be both thrilling and challenging. As Python continues to dominate the programming landscape, being well-prepared for common interview questions is essential. Let’s unravel the top 10 Python interview questions along with comprehensive answers, empowering you to navigate the technical terrain with confidence.

1. Question: What is Python, and what makes it stand out among other programming languages?

• Answer: Python is a high-level, interpreted, and dynamically-typed programming language. Its simplicity, readability, and versatility distinguish it. Python’s extensive libraries and frameworks, such as Django and Flask, contribute to its popularity for web development and data science.

2. Question: Explain the differences between Python 2 and Python 3.

• Answer: Python 3 is the latest version with significant syntax and feature enhancements over Python 2. Key changes include print function syntax, Unicode support, and improvements in integer division.

3. Question: What are Python decorators, and how do they work?

• Answer: Decorators are functions that modify the behavior of another function. They are applied using the “@” symbol. Decorators enable code reuse, enhance readability, and are commonly used in frameworks like Flask for route definitions.

4. Question: Describe the Global Interpreter Lock (GIL) in Python.

• Answer: The GIL is a mechanism in CPython that allows only one thread to execute Python bytecode at a time. This can impact multi-threaded Python programs, limiting their performance in CPU-bound tasks. However, it doesn’t hinder the performance of I/O-bound tasks.

5. Question: What is the purpose of the ‘self’ keyword in Python?

• Answer: In Python, ‘self’ is a convention used as the first parameter in instance methods. It refers to the instance of the class, allowing access to its attributes and methods within the method.

6. Question: Differentiate between lists and tuples in Python.

• Answer: Lists are mutable, meaning their elements can be modified after creation. Tuples, on the other hand, are immutable, making them faster but limiting their flexibility. Lists are defined with square brackets, while tuples use parentheses.

7. Question: Explain the concept of list comprehensions in Python.

• Answer: List comprehensions provide a concise way to create lists. They consist of an expression followed by a ‘for’ clause and, optionally, ‘if’ clauses. For example, [x**2 for x in range(10) if x % 2 == 0] generates a list of squares for even numbers.

8. Question: What is the purpose of the ‘yield’ keyword in Python?

• Answer: ‘yield’ is used in a function to turn it into a generator. It allows the function to pause and resume, maintaining its state. This is particularly useful for iterating over large datasets without loading the entire dataset into memory.

9. Question: Describe the Python ‘init’ method.

• Answer: ‘init’ is a special method in Python classes, called the constructor. It initializes the attributes of an object when it is created. It is the first method invoked when an object is instantiated.

10. Question: How does Python’s garbage collection work?

- **Answer:** Python uses automatic memory management through a built-in garbage collector. It tracks and reclaims memory occupied by objects that are no longer referenced. The cyclic garbage collector identifies and collects circular references.