ExceptionHandler: Decorator for Exception Handling

ExceptionHandler is an open-source Python library for simplyfying exception handling. It makes Python handling exception code cleaner and more readable.

Installation

To install ExceptionHandler, use pip with the following command:

pip install exception-handling-decorator

Releases

Latest releases of ExceptionHandler can be found at the PyPI repository: ExceptionHandler on PyPI

Source Code

The source code is stored at the GitHub repository: ExceptionHandler on GitHub

Getting started

Import ExceptionHandler:

from exception_handler import ExceptionHandler

Use @ExceptionHandler decorator with the following parameters:

exception=Exception - Exception(s) to be cаught. It can be of type Exception or its descendant or tuple[Exception].

handling_func=None - Function(s) to handle exception(s). It can be of type Callable or its descendant or tuple[Callable]. If handling_func is None, the exception will not be handled. If there more than one handling function (tuple[Callable]), every function will handle the corresponding Exception.

reraise=True - Indicates if the excaption(s) should be reraised. It can be of type bool or its descendant or tuple[bool]. If there more than one reraise (tuple[bool]), every tuple member will raise the corresponding Exception.

Example 1

The following code handles a ZeroDivisionError with classic try/except catching, prints and re-raise the exception:

def print_exception(ex):
    print(ex)

def divide_by_zero():
    try:
        return 1 / 0
    except ZeroDivisionError as e:
        print_exception(e)   
        raise

divide_by_zero()

We can simplify divide_by_zero() function by using @ExceptionHandler decorator:

@ExceptionHandler(exception=ZeroDivisionError, handling_func=print_exception, reraise=True)
def divide_by_zero():
    return 1 / 0   

The final code:

from exception_handler import ExceptionHandler
def print_exception(ex):
    print(ex)

@ExceptionHandler(exception=ZeroDivisionError, handling_func=print_exception, reraise=True)
def divide_by_zero():
    return 1 / 0  

divide_by_zero()  

Example 2

The following code raises randomly one of two custom exceptions:

import random
import logging

class SomeException(Exception):

    def __str__(self) -> str:
        return "SomeException message"

class SomeOtherException(Exception):
    def __str__(self) -> str:
        return "SomeOtherException message"

def get_rand_bool():
    """
    Returns random boolean value
    """
    rand_int = random.getrandbits(1)
    return bool(rand_int)

def log_exception(ex):
    logging.error(ex)


def print_exception(ex):
    print(ex)    


def do_something():
    if get_rand_bool():
        try:
            raise SomeException
        except SomeException as e:
            print_exception(e)
            raise
            
    try:
        raise SomeOtherException
    except SomeOtherException as e:
        log_exception(e)

do_something()

We can simplify do_something() function by using @ExceptionHandler decorator:

@ExceptionHandler(exception=(SomeException, SomeOtherException), 
                  handling_func=(print_exception, log_exception), 
                  reraise=(True,False))
def do_something():
    if get_rand_bool():
        raise SomeException
    raise SomeOtherException

The final code:

import random
from exception_handler import ExceptionHandler
import logging

class SomeException(Exception):

    def __str__(self) -> str:
        return "SomeException message"

class SomeOtherException(Exception):
    def __str__(self) -> str:
        return "SomeOtherException message"

def get_rand_bool():
    """
    Returns random boolean value
    """
    rand_int = random.getrandbits(1)
    return bool(rand_int)

def log_exception(ex):
    logging.error(ex)


def print_exception(ex):
    print(ex)  

@ExceptionHandler(exception=(SomeException, SomeOtherException), 
                  handling_func=(print_exception, log_exception), 
                  reraise=(True,False))
def do_something():
    if get_rand_bool():
        raise SomeException
    raise SomeOtherException  

do_something()