finally Block

Introduction#

In Python, error and exception handling is a crucial part of writing robust and reliable code. One key element of this structure is the finally block.

finally Block#

The finally block is a special type of block in Python’s try-except-finally structure. It is designed to house cleanup code, which will be executed regardless of whether an exception has occurred or not.

Here’s a basic example:

1try:
2    # Code that may raise an exception
3    x = 1 / 0
4except ZeroDivisionError:
5    # Code to run when a ZeroDivisionError is encountered
6    print("You can't divide by zero!")
7finally:
8    # Code to run no matter what happens above
9    print("Cleaning up...")

In this example, even though a ZeroDivisionError is raised in the try block, the finally block still runs.

finally and Exceptions#

Even if an exception isn’t handled in a corresponding except block, the finally block will be executed.

1try:
2    x = 1 / 0
3finally:
4    print("Cleaning up...")

This will return a ZeroDivisionError, yet “Cleaning up…” will still be printed to the console.

finally Without except#

A finally block can exist without an except block. This might be used when you want some code to run regardless of whether an exception occurs, but you don’t need to handle the exception in any specific way.

1try:
2    x = 1 / 0
3finally:
4    print("Cleaning up...")

Purpose of finally#

The finally block is typically used for cleanup actions that must always be completed. This can include closing files or network connections, or freeing up system resources.

Remember, the goal of a finally block is to enable the creation of robust code that can handle and recover from exception scenarios.