User:Niraj/Teaching-13

Teaching lesson plan 13 Subject: Python programming

Date: 29 Jan 2024

Time: 60 minutes

Period: 3rd

Teaching Item: Handling Exceptions in Python

Class: Bachelor

Objective:

Students will understand the concept of exceptions in Python, learn how to handle them using try, except, else, and finally blocks, and apply exception handling techniques to write robust and error-tolerant code.

Materials Needed:

• Python interpreter or IDE
• Projector

1. Introduction to Exceptions (10 mins)

• Define exceptions:
  • Exceptions are errors that occur during the execution of a program.
  • They can be caused by various reasons such as invalid input, file not found, or division by zero.
• Discuss the importance of handling exceptions in programming:
  • Prevent program crashes.
  • Provide graceful error messages to users.
  • Debug and troubleshoot code effectively.

2. try and except Blocks (15 mins)

• Explain the try and except blocks:
  • The try block contains the code that may raise an exception.
  • The except block catches and handles the exception.
• Demonstrate basic exception handling using try and except:
  • Show examples of catching specific exceptions and displaying custom error messages.
• Discuss multiple except blocks for handling different types of exceptions.

3. else Block (10 mins)

• Introduce the else block:
  • The else block is executed if no exceptions occur in the try block.
  • It is useful for executing code that should run only if the try block does not raise an exception.
• Show examples of using the else block in conjunction with try and except.

4. finally Block (10 mins)

• Discuss the finally block:
  • The finally block is always executed, whether an exception occurs or not.
  • It is useful for cleanup actions such as closing files or releasing resources.
• Demonstrate the usage of the finally block with try, except, and else.

5. Exception Hierarchy (10 mins)

• Explain the exception hierarchy in Python:
  • All exceptions are subclasses of the BaseException class.
  • Common exception classes include Exception, TypeError, ValueError, IOError, etc.
• Discuss the importance of understanding exception hierarchy for effective exception handling.

6. Exercise (10 mins)

• Provide a simple programming exercise where students:
  • Write a function that takes user input and handles exceptions such as invalid input or division by zero.
  • Use try, except, else, and finally blocks to handle different scenarios.

7. Conclusion (5 mins)

• Recap the key points covered in the lesson:
  • Exceptions are errors that occur during program execution.
  • Exception handling in Python involves try, except, else, and finally blocks.
  • Understanding the exception hierarchy helps in effective exception handling.
• Encourage students to practice exception handling in their own projects and explore advanced techniques such as raising custom exceptions.