How to use an error handling function on another function?

Question

I have a script, main.py, that runs a few functions from other scripts in the directory. I had the very unoriginal idea to send myself Slack notifications if specific functions ran correctly or failed, i.e. error handling. How would I use an error handling function located in a separate script - call the file slack_notifications.py - in my main.py script? This linked question starts to get at the answer, but it doesn't get to the calling the error function from somewhere else.

main.py script:

import scraper_file
import slack_notifications

# picture scrape variable
scrape_object = 'Barack Obama'

# scraper function called 
scraped_image = scraper_file.pic_scrape(scrape_object)

# error handling?
slack_notifications.scrape_status(scrape_object)

I have tried embedding the called scraper function into the scrape_status() function, like this: scraped_image = (slack_notifications.scrape_status(scraper_file.pic_scrape(scrape_object))) and a few other ways, but that doesn't really tell you if it ran successfully, right?

slack_notifications.py script:

testing = "dunderhead"

def scrape_status(x):

    # if this function gets a positive return from the scrape function
    # if this function gets any error from the scrape function
    try:
        x
        print(x + ' worked!')
    except:
        print(x + ' failed!')

if __name__ == '__main__':
    scrape_status(testing)

Is there a way to do this? I have been going off these instructions, too.

Answer 1

Code in your first link works because function input() was moved from outside error_handler() into inside error_handler() and it is executed inside `try/except.

Your code always runs function outside error handler scrape_status() and it sends only result from executed function - so it never runs it inside try/except.

You would have to send separatelly function's name (without () and arguments) and separatelly arguments - and then it can run it inside try/except

def scrape_status(function, *args):
    try:
        function(*args)
        print(function.__name__ + ' worked!')
    except:
        print(function.__name__ + ' failed!')

But it means you have to send function as

scrape_status(scraper_file.pic_scrape, scrape_object) 

instead of

scrape_status( scraper_file.pic_scrape(scrape_object) ) 

and this is not readable - so I don't know if it is good idea to create universal error handler.

---

Minimal working example

def scrape_status(function, *args, **kwargs):
    try:
        result = function(*args, **kwargs)  # some functions may return result
        print(function.__name__ + ' worked!')
        return result
    except:
        print(function.__name__ + ' failed!')

# ----

# this function needs `arg1, arg2` to work correctly
def testing(arg1, arg2):
    print(arg1, arg2)

# --- main ---
    
print('--- test 1 ---')    
# send funciton's name `testing` and argument(s) `'hello', 'world'`   
scrape_status(testing, 'hello', 'world')  # OK

print('--- test 2 ---')    
# send funciton's name `testing` without argument(s) 
scrape_status(testing)  # ERROR

Result:

--- test 1 ---
hello world
testing worked!
--- test 2 ---
testing failed!

---

EDIT:

I created new example using decorator based on answers in question General decorator to wrap try except in python?. Now code use readableand it needs to use decorator @scrape_status('') only when function is defined

@scrape_status('')
def testing(arg1, arg2):
    print(arg1, arg2)
  

Minimal working code:

def scrape_status():
  def decorate(function):
    def applicator(*args, **kwargs):
      try:
         result = function(*args, **kwargs)
         print(function.__name__ + ' worked!')
         return result
      except:
         print(function.__name__ + ' failed!')

    return applicator

  return decorate

# ----

# this function needs `arg1, arg2` to work correctly
@scrape_status()
def testing(arg1, arg2):
    print(arg1, arg2)

# --- main ---
  
print('--- test 1 ---')    
# send function's name `testing` and argument(s) `'hello', 'world'`   
testing('hello', 'world')  # OK

print('--- test 2 ---')    
# send function's name `testing` without argument(s) 
testing()  # ERROR

---

As I remeber there could be some module(s) with more complex decorators - ie. one decorator could repeate function 3 times if it was raising error. It could be uses to repeate question in input() if answer was wrong, or repeate downloading file if there was problem to download it.