Python interview questions with answers

 1. What is Python?

• Python is a high-level, interpreted programming language known for its simplicity and readability. It supports multiple programming paradigms, including procedural, object-oriented, and functional programming.

2. What are the key features of Python?

• Simple and easy to learn syntax: Python has a clean and readable syntax, making it easy for beginners to learn and use.
• Interpreted and dynamically typed: Python is an interpreted language, meaning code is executed line by line. It is dynamically typed, allowing variables to be assigned without specifying their type.
• High-level data structures: Python comes with built-in data structures like lists, dictionaries, sets, and tuples, making it suitable for handling complex data.
• Rich standard library: Python has a vast standard library with modules and packages for various tasks, from web development to scientific computing.
• Platform-independent: Python code can run on any platform with the Python interpreter installed, including Windows, macOS, and Linux.

3. What are the different data types in Python?

• Integer (int): Represents whole numbers.
• Float (float): Represents floating-point numbers.
• String (str): Represents sequences of characters.
• Boolean (bool): Represents True or False values.
• List: Ordered and mutable collection of items.
• Tuple: Ordered and immutable collection of items.
• Dictionary (dict): Unordered collection of key-value pairs.
• Set: Unordered collection of unique items.

4. What is the difference between list and tuple in Python?

• List:
  • Mutable: Elements can be added, removed, or modified.
  • Defined using square brackets [ ].
  • Slower than tuples due to dynamic resizing.
• Tuple:
  • Immutable: Elements cannot be changed after creation.
  • Defined using parentheses ( ).
  • Faster than lists due to fixed size.

5. How do you create a function in Python?

• Functions in Python are created using the def keyword followed by the function name and parameters. For example:

  python
  def greet(name):
      return f"Hello, {name}!"
  

6. What is a lambda function in Python?

• A lambda function is a small, anonymous function defined using the lambda keyword. It can take any number of arguments but can only have one expression. Lambda functions are commonly used as inline functions. For example:

  python
  add = lambda x, y: x + y
  

7. How do you handle exceptions in Python?

• Exceptions in Python are handled using try, except, and optionally finally blocks. For example:

  python
  try:
      result = 10 / 0
  except ZeroDivisionError:
      print("Division by zero!")
  

8. What are decorators in Python?

• Decorators are a powerful feature in Python that allow you to modify the behavior of functions or methods without changing their code. They are implemented using the @decorator_name syntax. For example:

  python
  def my_decorator(func):
      def wrapper():
          print("Something is happening before the function is called.")
          func()
          print("Something is happening after the function is called.")
      return wrapper
  
  @my_decorator
  def say_hello():
      print("Hello!")
  
  say_hello()
  

9. How do you read/write files in Python?

• Files in Python can be opened using the open() function, and data can be read or written using file object methods like read(), write(), readline(), and writelines(). For example:

  python
  with open("example.txt", "r") as file:
      data = file.read()
  

10. What is the difference between == and is in Python? - The == operator checks for equality of values, whereas the is operator checks for identity, i.e., whether two objects refer to the same memory location.

11. What is the purpose of __init__ method in Python classes? - The __init__ method is a special method in Python classes that is called automatically when a new instance of the class is created. It is used to initialize the object's attributes.

12. How do you handle modules and packages in Python? - Modules are Python files containing Python code, and packages are directories containing multiple modules. You can import modules or packages using the import statement. For example: python import math from mypackage import mymodule

These questions cover various aspects of Python and can help assess a candidate's understanding and proficiency in the language.