How do you create custom exceptions?

Unlocking Python Expertise with UrbanPro's Python Training Online Coaching

Introduction:

As an experienced Python Training tutor registered on UrbanPro.com, I'm delighted to guide you through the process of creating custom exceptions in Python. At UrbanPro, we pride ourselves on offering the best online coaching for Python Training, ensuring learners receive top-notch guidance from skilled tutors and coaching institutes.

Creating Custom Exceptions in Python: A Step-by-Step Guide

1. Understanding the Need for Custom Exceptions:

   • Custom exceptions allow developers to handle specific errors in a more tailored manner.
   • They enhance code readability and debugging by providing context to potential issues.

2. Defining a Base Exception Class:

   • Start by creating a base exception class that inherits from Python's built-in Exception class.
   • This forms the foundation for your custom exceptions.
   python

• class CustomExceptionBase(Exception): pass

• Creating Specific Custom Exceptions:

  • Extend the base class to create custom exceptions with distinct functionalities.
  • UrbanPro's Python Training online coaching emphasizes the importance of naming conventions for clear communication.
  python
• class InvalidInputError(CustomExceptionBase): def __init__(self, message="Invalid input detected. Please check your data."): super().__init__(message) class FileNotFoundError(CustomExceptionBase): def __init__(self, file_name): super().__init__(f"File '{file_name}' not found. Verify the file path.")

• Raising Custom Exceptions:

  • Utilize the raise keyword to trigger your custom exceptions based on specific conditions.
  python
• def process_file(file_path): if not os.path.exists(file_path): raise FileNotFoundError(file_path) # Additional processing logic

• Handling Custom Exceptions:

  • Implement try-except blocks to handle custom exceptions gracefully.
  • This ensures a smoother user experience and facilitates effective troubleshooting.
  python