How to use the handprint.ui.alert function in handprint

service = add_creds.lower()
        if service not in services_list():
            alert('Unknown service: "{}". {}', service, hint)
            exit(1)
        if not files or len(files) > 1:
            alert('Option {}a requires one file. {}', prefix, hint)
            exit(1)
        creds_file = files[0]
        if not readable(creds_file):
            alert('File not readable: {}', creds_file)
            exit(1)
        Credentials.save_credentials(service, creds_file)
        inform('Saved credentials for service "{}".', service)
        exit(0)
    if no_grid and not extended and not compare:
        alert('{0}G without {0}e or {0}c produces no output. {1}', prefix, hint)
        exit(1)
    if any(item.startswith('-') for item in files):
        alert('Unrecognized option in arguments. {}', hint)
        exit(1)
    if not files and from_file == 'F':
        alert('Need images or URLs to have something to do. {}', hint)
        exit(1)
    if relaxed and not compare:
        warn('Option {0}r without {0}c has no effect. {1}', prefix, hint)

    services = services_list() if services == 'S' else services.lower().split(',')
    if not all(s in services_list() for s in services):
        alert('"{}" is not a known services. {}', services, hint)
        exit(1)

    base_name  = 'document' if base_name == 'B' else base_name

compare    = 'relaxed' if (compare and relaxed) else compare
    threads    = int(max(1, available_cpus()/2 if threads == 'T' else int(threads)))

    # Do the real work --------------------------------------------------------

    try:
        body = MainBody(base_name, extended, from_file, output_dir, threads)
        body.run(services, files, make_grid, compare)
    except (KeyboardInterrupt, UserCancelled) as ex:
        if __debug__: log('received {}', sys.exc_info()[0].__name__)
        inform('Quitting.')
        exit(0)
    except Exception as ex:
        if debugging:
            import traceback
            alert('{}\n{}', str(ex), traceback.format_exc())
            import pdb; pdb.set_trace()
        else:
            alert(str(ex))
            exit(2)
    inform('Done.')

exit(1)
        creds_file = files[0]
        if not readable(creds_file):
            alert('File not readable: {}', creds_file)
            exit(1)
        Credentials.save_credentials(service, creds_file)
        inform('Saved credentials for service "{}".', service)
        exit(0)
    if no_grid and not extended and not compare:
        alert('{0}G without {0}e or {0}c produces no output. {1}', prefix, hint)
        exit(1)
    if any(item.startswith('-') for item in files):
        alert('Unrecognized option in arguments. {}', hint)
        exit(1)
    if not files and from_file == 'F':
        alert('Need images or URLs to have something to do. {}', hint)
        exit(1)
    if relaxed and not compare:
        warn('Option {0}r without {0}c has no effect. {1}', prefix, hint)

    services = services_list() if services == 'S' else services.lower().split(',')
    if not all(s in services_list() for s in services):
        alert('"{}" is not a known services. {}', services, hint)
        exit(1)

    base_name  = 'document' if base_name == 'B' else base_name
    from_file  = None if from_file == 'F' else from_file
    output_dir = None if output_dir == 'O' else output_dir
    compare    = 'relaxed' if (compare and relaxed) else compare
    threads    = int(max(1, available_cpus()/2 if threads == 'T' else int(threads)))

    # Do the real work --------------------------------------------------------

if version:
        print_version()
        exit(0)
    if list:
        inform('Known services: {}', ', '.join(services_list()))
        exit(0)

    print_intro(ui)

    if add_creds != 'A':
        service = add_creds.lower()
        if service not in services_list():
            alert('Unknown service: "{}". {}', service, hint)
            exit(1)
        if not files or len(files) > 1:
            alert('Option {}a requires one file. {}', prefix, hint)
            exit(1)
        creds_file = files[0]
        if not readable(creds_file):
            alert('File not readable: {}', creds_file)
            exit(1)
        Credentials.save_credentials(service, creds_file)
        inform('Saved credentials for service "{}".', service)
        exit(0)
    if no_grid and not extended and not compare:
        alert('{0}G without {0}e or {0}c produces no output. {1}', prefix, hint)
        exit(1)
    if any(item.startswith('-') for item in files):
        alert('Unrecognized option in arguments. {}', hint)
        exit(1)
    if not files and from_file == 'F':
        alert('Need images or URLs to have something to do. {}', hint)

inform('Known services: {}', ', '.join(services_list()))
        exit(0)

    print_intro(ui)

    if add_creds != 'A':
        service = add_creds.lower()
        if service not in services_list():
            alert('Unknown service: "{}". {}', service, hint)
            exit(1)
        if not files or len(files) > 1:
            alert('Option {}a requires one file. {}', prefix, hint)
            exit(1)
        creds_file = files[0]
        if not readable(creds_file):
            alert('File not readable: {}', creds_file)
            exit(1)
        Credentials.save_credentials(service, creds_file)
        inform('Saved credentials for service "{}".', service)
        exit(0)
    if no_grid and not extended and not compare:
        alert('{0}G without {0}e or {0}c produces no output. {1}', prefix, hint)
        exit(1)
    if any(item.startswith('-') for item in files):
        alert('Unrecognized option in arguments. {}', hint)
        exit(1)
    if not files and from_file == 'F':
        alert('Need images or URLs to have something to do. {}', hint)
        exit(1)
    if relaxed and not compare:
        warn('Option {0}r without {0}c has no effect. {1}', prefix, hint)

exit(0)
    if no_grid and not extended and not compare:
        alert('{0}G without {0}e or {0}c produces no output. {1}', prefix, hint)
        exit(1)
    if any(item.startswith('-') for item in files):
        alert('Unrecognized option in arguments. {}', hint)
        exit(1)
    if not files and from_file == 'F':
        alert('Need images or URLs to have something to do. {}', hint)
        exit(1)
    if relaxed and not compare:
        warn('Option {0}r without {0}c has no effect. {1}', prefix, hint)

    services = services_list() if services == 'S' else services.lower().split(',')
    if not all(s in services_list() for s in services):
        alert('"{}" is not a known services. {}', services, hint)
        exit(1)

    base_name  = 'document' if base_name == 'B' else base_name
    from_file  = None if from_file == 'F' else from_file
    output_dir = None if output_dir == 'O' else output_dir
    compare    = 'relaxed' if (compare and relaxed) else compare
    threads    = int(max(1, available_cpus()/2 if threads == 'T' else int(threads)))

    # Do the real work --------------------------------------------------------

    try:
        body = MainBody(base_name, extended, from_file, output_dir, threads)
        body.run(services, files, make_grid, compare)
    except (KeyboardInterrupt, UserCancelled) as ex:
        if __debug__: log('received {}', sys.exc_info()[0].__name__)
        inform('Quitting.')

def _converted_file(self, file, to_format, dest_dir):
        basename = path.basename(filename_basename(file))
        new_file = path.join(dest_dir, basename + '.handprint.' + to_format)
        if path.exists(new_file):
            inform('Using existing converted image in {}', relative(new_file))
            return new_file
        else:
            inform('Converting to {} format: {}', to_format, relative(file))
            (converted, error) = converted_image(file, to_format, new_file)
            if error:
                alert('Failed to convert {}: {}', relative(file), error)
                return None
            return converted

'''Run all requested services on the image indicated by "item", using
        "index" and "base_name" to construct a download copy of the item if
        it has to be downloaded from a URL first.
        '''
        # Shortcuts to make the code more readable.
        services = self._services

        inform('Starting on {}', styled(item, 'white'))
        try:
            (item_file, item_fmt) = self._get(item, base_name, index)
            if not item_file:
                return

            dest_dir = self._output_dir if self._output_dir else path.dirname(item_file)
            if not writable(dest_dir):
                alert('Cannot write output in {}.', dest_dir)
                return

            # Normalize input image to the lowest common denominator.
            image = self._normalized(item, item_fmt, item_file, dest_dir)
            if not image.file:
                warn('Skipping {}', relative(item_file))
                return

            # Send the file to the services and get Result tuples back.
            if self._num_threads == 1:
                # For 1 thread, avoid thread pool to make debugging easier.
                results = [self._send(image, s) for s in services]
            else:
                with ThreadPoolExecutor(max_workers = self._num_threads) as tpe:
                    results = list(tpe.map(self._send, repeat(image), iter(services)))

name_tail = '.handprint' + file_ext
        new_file = file if name_tail in file else filename_basename(file) + name_tail
        if path.exists(new_file) and readable(new_file):
            (image_width, image_height) = image_dimensions(new_file)
            if image_width < max_width and image_height < max_height:
                inform('Using reduced image found in {}', relative(new_file))
                return new_file
            else:
                # We found a "-reduced" file, perhaps from a previous run, but
                # for the current set of services, dimension are too large.
                if __debug__: log('existing resized file larger than {}x{}: {}',
                                  max_width, max_height, new_file)
        inform('Dimensions too large; reducing dimensions: {}', relative(file))
        (resized, error) = reduced_image_dimensions(file, new_file, max_width, max_height)
        if error:
            alert('Failed to re-dimension {}: {}', relative(file), error)
            return None
        return resized

def _save(self, result, file):
        # First perform some sanity checks.
        if result is None:
            warn('No data for {}', file)
            return
        if isinstance(result, tuple):
            # Assumes 2 elements: data, and error
            (data, error) = result
            if error:
                alert('Error: {}', error)
                warn('Unable to write {}', file)
                return
            else:
                result = data

        if __debug__: log('writing output to file {}', relative(file))
        if isinstance(result, str):
            with open(file, 'w') as f:
                f.write(result)
        elif isinstance(result, io.BytesIO):
            with open(file, 'wb') as f:
                shutil.copyfileobj(result, f)
        else:
            # There's no other type in the code, so if we get here ...
            raise InternalError('Unexpected data in save_output() -- please report this.')