seviper 0.0.4

A simple and easy to use library to catch and handle exceptions.

Seviper - Error handling framework to catch 'em all

Features

This framework provides several error handlers to catch errors and call callback functions to handle these errors (or successes). It comes fully equipped with:

• A decorator to handle errors in functions or coroutines
• A decorator to retry a function or coroutine if it fails (can be useful for network requests)
• A context manager to handle errors in a block of code

Additionally, if you use aiostream (e.g. using pip install seviper[aiostream]), you can use the following features:

• The stream.map (or pipe.map, analogous to the aiostream functions) function to run the function, catch all exceptions and call the error handler if an exception occurs. Additionally, filters out all failed results.

Installation

pip install seviper

or optionally:

pip install seviper[aiostream]

Usage

Here is a more or less complex example as showcase of the features of this library:

import asyncio
import logging
import sys
import aiostream
import error_handler

logging.basicConfig(stream=sys.stdout, level=logging.DEBUG, force=True)
logger = logging.root
op = aiostream.stream.iterate(range(10))


def log_error(error: Exception, num: int):
    """Only log error and reraise it"""
    logger.error("double_only_odd_nums_except_5 failed for input %d. ", num)
    raise error


@error_handler.decorator(on_error=log_error)
async def double_only_odd_nums_except_5(num: int) -> int:
    if num % 2 == 0:
        raise ValueError(num)
    with error_handler.context_manager(on_success=lambda: logging.info("Success: %s", num)):
        if num == 5:
            raise RuntimeError("Another unexpected error. Number 5 will not be doubled.")
        num *= 2
    return num


def catch_value_errors(error: Exception, _: int):
    if not isinstance(error, ValueError):
        raise error


def log_success(result_num: int, provided_num: int):
    logger.info("Success: %d -> %d", provided_num, result_num)


op = op | error_handler.pipe.map(
    double_only_odd_nums_except_5,
    on_error=catch_value_errors,
    on_success=log_success,
    wrap_secured_function=True,
    suppress_recalling_on_error=False,
)

result = asyncio.run(aiostream.stream.list(op))

assert result == [2, 6, 5, 14, 18]

This outputs:

ERROR:root:double_only_odd_nums_except_5 failed for input 0.
INFO:root:Success: 2
INFO:root:Success: 1 -> 2
ERROR:root:double_only_odd_nums_except_5 failed for input 2.
INFO:root:Success: 6
INFO:root:Success: 3 -> 6
ERROR:root:double_only_odd_nums_except_5 failed for input 4.
INFO:root:Success: 5 -> 5
ERROR:root:double_only_odd_nums_except_5 failed for input 6.
INFO:root:Success: 14
INFO:root:Success: 7 -> 14
ERROR:root:double_only_odd_nums_except_5 failed for input 8.
INFO:root:Success: 18
INFO:root:Success: 9 -> 18

How to use this Repository on Your Machine

Please refer to the respective section in our Python template repository to learn how to use this repository on your machine.

Contribute

You are very welcome to contribute to this template repository by opening a pull request against the main branch.