exceptiongroup

1.3.1 · active · verified Sat Mar 28

A backport of PEP 654, providing exception groups and the 'except*' syntax for Python versions prior to 3.11. Current version: 1.3.1. Released on November 21, 2025. Maintained by The Trio Collective.

Warnings

breaking The 'except*' syntax introduced in PEP 654 is not available in Python versions prior to 3.11. Ensure compatibility with your Python version.
Fix: Use the 'exceptiongroup' package to backport exception groups and 'except*' syntax to earlier Python versions.
gotcha The 'catch' function from 'exceptiongroup' is necessary to handle exception groups in Python versions prior to 3.11. Omitting it will result in unhandled exceptions.
Fix: Import and use 'catch' from 'exceptiongroup' to handle exception groups appropriately.

Install

pip install exceptiongroup Install exceptiongroup

Imports

BaseExceptionGroup
```
from exceptiongroup import BaseExceptionGroup
```
Correct import path for BaseExceptionGroup
ExceptionGroup
```
from exceptiongroup import ExceptionGroup
```
Correct import path for ExceptionGroup
catch
```
from exceptiongroup import catch
```
Correct import path for catch function

Quickstart

An example demonstrating the use of exception groups to handle multiple exceptions raised concurrently in Python 3.11 and later.

import asyncio
from exceptiongroup import BaseExceptionGroup, catch

async def read_file(filename):
    with open(filename) as f:
        data = f.read()
    return data

async def main():
    try:
        async with asyncio.TaskGroup() as g:
            g.create_task(read_file('unknown1.txt'))
            g.create_task(read_file('unknown2.txt'))
        print('All done')
    except* FileNotFoundError as eg:
        for e in eg.exceptions:
            print(e)

asyncio.run(main())

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