How to handle exceptions ?

[sumit-158]

First Check

• I added a very descriptive title to this issue.
• I used the GitHub search to find a similar issue and didn't find it.
• I searched the Asyncer documentation, with the integrated search.
• I already searched in Google "How to X in Asyncer" and didn't find any information.
• I already read and followed all the tutorial in the docs and didn't find an answer.
• I already checked if it is not related to Asyncer but to AnyIO.
• I already checked if it is not related to Asyncer but to Trio.

Commit to Help

• I commit to help with one of those options 👆

Example Code

import asyncer
import logging
from typing import Union

from fastapi import FastAPI

async def func1(name: str):
    return {"message": f"Hello {name} form func1"}


async def func2():
    return {"message": f"Hello {name} form func2"}


@app.get("/test")
async def knowledge_panel(name_str: str):
    async with asyncer.create_task_group() as task_group:
        try:
            soon_value1 = task_group.soonify(func1)(name=name_str)
        except Exception:
            logging.exception()
        try:
            soon_value2 = task_group.soonify(func2)(name=name_str)
        except Exception:
            logging.exception()
    data = [soon_value1.value, soon_value2.value]
    return data

Description

• How to handle an exception like here soon_value2 will throw an error, then how could I catch the exceptions and return user only single data rather than crashing the whole program?

Operating System

Windows

Operating System Details

No response

asyncer Version

0.0.1

Python Version

Python 3.10.5

Additional Context

No response

[tiangolo]

I assume you solved it, thanks for closing the issue 👍

[sumit-158]

@tiangolo not actually, I tried something else but it's not that robust and clean.

[gitierrez]

@sumit-158 how did you handle this? I'm having the exact same problem and can't find anything about it.

[sumit-158]

@gitierrez I used an async "exception_wrapper" decorator.
Here - https://github.com/openfoodfacts/facets-knowledge-panels/blob/6eda756eca7703f9cf0e1a7fad9cf868366df12d/app/exception_wrapper.py#L5

[MarkParker5]

I see there 3 options:

1. Handle exceptions inside func1 (func2)

async def func1(name: str):
    try:
        return {"message": f"Hello {name} form func1"}
    except:
        return {} # fallback value

...

2. Add a decorator to wrap functions

def catch(func):
    async def wrapped(*args, **kwargs):
        try:
            return await func(*args, **kwargs)
        except:
            return None
    return wrapped

# apply decorator
@catch
def func1(...):
    ...
    
def func2(...):
    ...
    
@app.get("/test")
async def knowledge_panel(name_str: str):
    async with asyncer.create_task_group() as task_group:
        soon_value1 = task_group.soonify(func1)(name=name_str) # catch applied to all func1
        soon_value2 = task_group.soonify(catch(func2))(name=name_str) # or wrap inly exact call
    data = [soon_value1.value, soon_value2.value] # don't forget to handle None case
    return data

3. Wrap entire group call

@app.get("/test")
async def knowledge_panel(name_str: str):
    try:
        async with asyncer.create_task_group() as task_group:
            soon_value1 = task_group.soonify(func1)(name=name_str)
            soon_value2 = task_group.soonify(func2)(name=name_str)
        data = [soon_value1.value, soon_value2.value]
    except:
        data = []
    return data