FileNotFoundError thrown due to file name in file, rather than file itself

Cameron Simpson cs at cskk.id.au
Mon Nov 11 16:17:46 EST 2024


On 11Nov2024 18:24, dieter.maurer at online.de <dieter.maurer at online.de> wrote:
>Loris Bennett wrote at 2024-11-11 15:05 +0100:
>>I have the following in my program:
>>    try:
>>        logging.config.fileConfig(args.config_file)
>>        config = configparser.ConfigParser()
>>        config.read(args.config_file)
>>        if args.verbose:
>>            print(f"Configuration file: {args.config_file}")
>>    except FileNotFoundError:
>>        print(f"Error: configuration file {args.config_file} not found.  Exiting.")
>
>Do not replace full error information (including a traceback)
>with your own reduced error message.
>If you omit your "try ... except FileNotFoundError`
>(or start the `except` clause with a `raise`), you
>will learn where in the code the exception has been raised
>and likely as well what was not found (Python is quite good
>with such error details).

Actually, file-not-found is pretty well defined - the except action 
itself is fine in that regard.

[...]
>>2. In terms of generating a helpful error message, how should one
>>   distinguish between the config file not existing and the log file not
>>   existing?

Generally you should put a try/except around the smallest possible piece 
of code. So:

     config = configparser.ConfigParser()
     try:
         config.read(args.config_file)
     except FileNotFoundError as e:
         print(f"Error: configuration file {args.config_file} not found: {e}")

This way you know that the config file was missing.

Cheers,
Cameron Simpson <cs at cskk.id.au>


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