What is an exception, difference between exception and error,exception handling inpython ( try block, except block, else block and finally block

1. What is an Exception? An exception is an event that occurs during the execution of a program that disrupts the normal flow of the program's instructions. In general, when a Python script encounters a situation that it cannot cope with, it raises an exception. An exception is a Python object that represents an error.

2. Difference between Exception and Error: Both exceptions and errors are derived from the same class in Python, but they are different. An error is a serious problem that a reasonable application should not try to catch, while an exception is a problem that the application can handle.

3. Exception Handling in Python: Python provides a way to handle the exception so that the code can be executed without any interruption. If we have some suspicious code that may raise an exception, we can defend our program by placing the suspicious code in a try: block.

• Try Block: The try block lets you test a block of code for errors. The code inside the try block will execute when there is no error in the program. If there is an error, it will pass the control to the except block.

• Except Block: The except block lets you handle the error. The code inside the except block will execute whenever the program encounters some error in the preceding try block.

• Else Block: You can use the else keyword to define a block of code to be executed if no errors were raised in the try block. This must be placed after all the except blocks.

• Finally Block: The finally block lets you execute code, regardless of the result of the try- and except blocks. This block will always be executed, regardless if the try block raises an error or not. This is generally used to release external resources.

For example:

try:
   # You do your operations here
   # ...
except ExceptionI:
   # If there is ExceptionI, then execute this block.
   # ...
except ExceptionII:
   # If there is ExceptionII, then execute this block.
   # ...
else:
   # If there is no exception then execute this block. 
finally:
  # This code block would always be executed.

This is a basic overview of exception handling in Python. There are more specific types of exceptions and errors in Python, but this should give you a good starting point.