How to create optional tuple return or unpack

Question

I want to send tuple back if function returns error message and the data if success:

Example function:

def test(args):
   if (some success here):
     return data
   return None, error_message

Call:

data, error_msg = test(args)
if error_msg:
   return somehttpresponse(error_msg, 400)
return somehttpresponse(data, 200)

How can I achieve this in python? Or is there any other clean way to return error message without compromising the return data on success?

Answer 1

So far I used Exception:

Example function:

def test(args):
   if (some success here):
     return data
   raise ValueError(error_message)
   return None

Call:

try:
   data = test(args)
   return somehttpresponse(data, 200)
except ValueError as err:
   return somehttpresponse(err, 400)

Not sure if it's the most efficient way. still hoping someone has an answer