Error_Handling Module

Error handling for expected / unexpected exceptions.

The default handler will…

• Call print() after catching a KeyboardInterrupt, before exiting

• Exit gracefully after catching a BrokenPipeError (often caused by piping output to a tool like tail)

Note

Parameters defined in a base Command will be processed in the context of that Command. I.e., if a valid subcommand argument was provided, but an Option defined in the parent Command has an invalid value, then the exception that is raised about that invalid value will be raised before transferring control to the subcommand’s error handler.

author:

Doug Skrypa

class cli_command_parser.error_handling.ErrorHandler

Bases: object

exc_handler_map: dict[Type[BaseException], Handler]

register(handler: Callable[[BaseException], bool | None], *exceptions: Type[BaseException])

unregister(*exceptions: Type[BaseException])

__call__(*exceptions: Type[BaseException])

classmethod cls_handler(*exceptions: Type[BaseException])

iter_handlers(exc_type: Type[BaseException], exc: BaseException) → Iterator[Callable[[BaseException], bool | None]]

copy() → ErrorHandler

class cli_command_parser.error_handling.NullErrorHandler

Bases: object

class cli_command_parser.error_handling.Handler(exc_cls: Type[BaseException], handler: Callable[[BaseException], bool | None])

Bases: object

Wrapper around an exception class and the handler for it to facilitate sorting to select the most specific handler for a given exception.

exc_cls

handler

cli_command_parser.error_handling.error_handler: ErrorHandler = <ErrorHandler[handlers=2]>

Default base ErrorHandler

cli_command_parser.error_handling.handle_kb_interrupt(exc: KeyboardInterrupt) → int

Handles KeyboardInterrupt by calling print() to avoid ending the program in a way that causes the next terminal prompt to be printed on the same line as the last (possibly incomplete) line of output.

cli_command_parser.error_handling.no_exit_handler: ErrorHandler = <ErrorHandler[handlers=3]>

An ErrorHandler that does not call sys.exit() for CommandParserExceptions

cli_command_parser.error_handling.extended_error_handler: ErrorHandler = <ErrorHandler[handlers=2]>

The default ErrorHandler (extends error_handler)