Refactor try and Except codeblocks in Python

Question

Currently my app is working with several external APIs, and those functions can raise some kind of error, and I would like to be aware of all kind of situations and don't crash my app. In the following piece of code you can see my function, using slack api (it's just an example, not real example), and you can see how I'm creating a space giving the name and the emails. That function can returns several errors, like APIerror, TypeError... etc etc

Also you can see, all the functions in that file, can raise some errors so it is using try and except and try to don't break our app. In the except part, I don't want to do anything special, just return the error or I don't know, raise an custom error. In the future would be cool if I can enqueue that task if something goes wrong.

slack_client.py

def create_space():
  try:
    slack_api.create.space(spaceName='space name', email=emails)
  except (...):
    ...

def delete_space():
  try:
    slack_api.delete.space(spaceId=space_id)
  except (...):
    ...

I would like to refactor the try and except part, because I don't want to copy and paste try and except during all my slack_client class, but in case the connection is down, or some parameter is wron, the "Slack" API will raise me an error.

I thought about create a class, to run each function inside try and catch, but it's a bit weird and I will loose the arguments part like "spaceName='space name'", which I think it's really cool and clear.

def execute_func(func, *args):
  try:
     func(args)
  except (..):
     ...

So would like some help for this kind of situation, because handle external API is not always really easy... (at the moment working with 2 external APIs)

Answer 1

You can catch any exception that is thrown and capture it in a variable to log or raise. You could even raise your own custom exception. Something like this should work:

First create your exception:

class CustomSlackException(Exception):
    pass

Then raise it when the API you called throws some exception:

try:
    slack_api.create.space(spaceName='space name', email=emails)
except Exception as e:
    print(e)
    raise CustomSlackException("Custom error message!")

Now you can catch your exception and handle it as needed.

Answer 2

In a previous life I used VAX/VMS and still remember great pleasure at discoverting LIB$SIG_TO_RET which converted a signal to a return value. You can do exactly the same in not many lines of Python, along the lines you indicated

def execute_func(func, *args, **kwargs):
  try:
     result = func( *args, **kwargs)
     return (True, result)

  except Exception as exc:
       return ( False, exc)

Usage

result = execute_func( func, a1, a2, ... k1=v1, k2=v2, ...)
if  result[0]:
    func_result = result[1] # if it's  useful
    ...
else:
     # it went wrong, deal with the exception
     caught_exception = result[1]
     print( caught_exception)