noexcept 1.5.4

A callable interface for structured exceptions

No Exceptions

A callable interface for structured exceptions in Python, allowing dynamic registration of error codes, soft (non-raising) codes, exception propagation with context, and grouping multiple errors.

Features

• Dynamic Error Codes: Register custom error codes with default complaints at runtime.
• Soft Errors: Define codes that don’t immediately raise exceptions, useful for warning accumulation.
• Error Propagation: Wrap existing exceptions under new error codes while preserving context.
• Exception Linking: Attach underlying exceptions to your custom errors for full traceability.
• ExceptionGroup Support: Bundle multiple error codes into a single ExceptionGroup.
• Rich String Output: Automatically include codes, complaints, linked exceptions, and stack traces when converting to string.

Installation

Requires Python 3.11 or newer.

With PIP

pip install noexcept

With GitHub

pip install git+https://github.com/HiDrNikki/noexcept.git

pip install git+https://github.com/HiDrNikki/noexcept.git@v1.2.2

pip install -e git+https://github.com/HiDrNikki/noexcept.git@main#egg=noexcept

Quick Start

Import the callable exception handler and register your error codes:

from noexcept import no

Register codes at startup

no.likey(404, "Not Found")            # Standard error
no.likey(500, "Server Error")         # Standard error
no.likey(123, "Soft Error", soft=True)  # Soft (non-raising)

Raising an Exception

from noexcept import no

try:
    no(404)
except no.way as noexcept:
    print(str(noexcept))
    # [404]
    # Not Found

Soft Errors

Soft codes don’t immediately raise:

no(123)  # No exception is thrown because code 123 is registered as soft

Propagating Errors

Wrap an existing exception under a new code:

try:
    raise ValueError("underlying issue")
except ValueError as ve:
    try:
        no(500, ve)  # Raises a no.way with 500 as the linked ValueError
    except no.way as noexcept:
        print(noexcept)

Linking Underlying Exceptions

Add an existing exception to a new code without raising immediately:

try:
    raise KeyError("missing key")
except KeyError as ke:
    no(404, ke, soften=True)

Grouping Multiple Errors

Bundle multiple codes in one go:

try:
    no([404, 500])
except ExceptionGroup as eg:
    for subexc in eg.exceptions:
        print(subexc)

no.go

no.go provides a context manager for cleanly handling exceptions:

with no.go(404):
    raise ValueError("Original issue")  # Automatically wrapped under code 404

It can also be used in line to run a callable, and raise an error code if it fails.

result = no.go(404, myFunction, *args, **kwargs, soften = True)

In both cases the raw error that is thrown is linked to whatever code is passed.

no.bueno

no.bueno indicates if any soft errors have yet been registered:

no(123)
if no.bueno:
    print("Issues detected")

no.nos

no.nos contains details of all registered error codes:

print(no.nos)
# {404: 'Not Found', 500: 'Server Error', 123: 'Soft Error'}

no.complaints

no.complaints accumulates soft error messages:

no(123)
no(123, "Extra warning detail")

print(no.complaints)
# ['Soft Error', 'Soft Error: Extra warning detail']

API Reference

Import the handler

from noexcept import no

Register error codes

no.likey(code: int, complaint: str, soften: bool = False)

Raise exceptions

no(code: int | list[int] | Exception, complaint: str = None, soften: bool = False)

Base exception type

no.way

Inline error safe code execution, or context manager

no.go

A boolean indicating whether any soft errors have been triggered yet

no.bueno

A dictionary containing all the currently triggered codes

no.nos

A flat list of all of the error messages

no.complaints

Clears the pending exception, along with all codes and messages

no.dice()

Contributing

Contributions are welcome! Please open issues and pull requests on GitHub.

License

This project is licensed under the MIT License. See LICENSE for details.

Authored by Nichola Walch [e-mail]