How to use the gphoto2.gp_camera_new function in gphoto2

def main():
    logging.basicConfig(
        format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
    callback_obj = gp.check_result(gp.use_python_logging())
    camera = gp.check_result(gp.gp_camera_new())
    gp.check_result(gp.gp_camera_init(camera))
    print('Getting list of files')
    files = list_files(camera)
    if not files:
        print('No files found')
        return 1
    path = files[0]
    print('Copying %s to memory' % path)
    folder, name = os.path.split(path)
    camera_file = gp.check_result(gp.gp_camera_file_get(
        camera, folder, name, gp.GP_FILE_TYPE_NORMAL))
##    # read file data using 'slurp' and a buffer allocated in Python
##    info = gp.check_result(
##        gp.gp_camera_file_get_info(camera, folder, name))
##    file_data = bytearray(info.file.size)
##    count = gp.check_result(gp.gp_file_slurp(camera_file, file_data))

def main():
    logging.basicConfig(
        format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
    callback_obj = gp.check_result(gp.use_python_logging())
    camera = gp.check_result(gp.gp_camera_new())
    gp.check_result(gp.gp_camera_init(camera))
    print('Getting list of files')
    files = list_files(camera)
    if not files:
        print('No files found')
        return 1
    path = files[0]
    print('Copying %s to memory in 100 kilobyte chunks' % path)
    folder, name = os.path.split(path)
    file_info = gp.check_result(gp.gp_camera_file_get_info(
        camera, folder, name))
    data = bytearray(file_info.file.size)
    view = memoryview(data)
    chunk_size = 100 * 1024
    offset = 0
    while offset < len(data):

def main():
    # use Python logging
    logging.basicConfig(
        format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
    callback_obj = gp.check_result(gp.use_python_logging())
    # get user value
    if len(sys.argv) != 2:
        print('One command line parameter required')
        return 1
    try:
        value = int(sys.argv[1])
    except:
        print('Integer parameter required')
        return 1
    # open camera connection
    camera = gp.check_result(gp.gp_camera_new())
    gp.check_result(gp.gp_camera_init(camera))
    # get configuration tree
    config = gp.check_result(gp.gp_camera_get_config(camera))
    # find the capture target config item
    capture_target = gp.check_result(
        gp.gp_widget_get_child_by_name(config, 'capturetarget'))
    # check value in range
    count = gp.check_result(gp.gp_widget_count_choices(capture_target))
    if value < 0 or value >= count:
        print('Parameter out of range')
        return 1
    # set value
    value = gp.check_result(gp.gp_widget_get_choice(capture_target, value))
    gp.check_result(gp.gp_widget_set_value(capture_target, value))
    # set config
    gp.check_result(gp.gp_camera_set_config(camera, config))

def main():
    logging.basicConfig(
        format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
    callback_obj = gp.check_result(gp.use_python_logging())
    computer_files = list_computer_files()
    camera = gp.check_result(gp.gp_camera_new())
    gp.check_result(gp.gp_camera_init(camera))
    print('Getting list of files from camera...')
    camera_files = list_camera_files(camera)
    if not camera_files:
        print('No files found')
        return 1
    print('Copying files...')
    for path in camera_files:
        info = get_camera_file_info(camera, path)
        timestamp = datetime.fromtimestamp(info.file.mtime)
        folder, name = os.path.split(path)
        dest_dir = get_target_dir(timestamp)
        dest = os.path.join(dest_dir, name)
        if dest in computer_files:
            continue
        print('%s -> %s' % (path, dest_dir))

def main():
    # use Python logging
    logging.basicConfig(
        format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
    callback_obj = gp.check_result(gp.use_python_logging())
    # open camera connection
    camera = gp.check_result(gp.gp_camera_new())
    gp.check_result(gp.gp_camera_init(camera))
    # get configuration tree
    config = gp.check_result(gp.gp_camera_get_config(camera))
    # find the capture target config item
    capture_target = gp.check_result(
        gp.gp_widget_get_child_by_name(config, 'capturetarget'))
    # print current setting
    value = gp.check_result(gp.gp_widget_get_value(capture_target))
    print('Current setting:', value)
    # print possible settings
    for n in range(gp.check_result(gp.gp_widget_count_choices(capture_target))):
        choice = gp.check_result(gp.gp_widget_get_choice(capture_target, n))
        print('Choice:', n, choice)
    # clean up
    gp.check_result(gp.gp_camera_exit(camera))
    return 0

def main():
    logging.basicConfig(
        format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
    callback_obj = gp.check_result(gp.use_python_logging())
    camera = gp.check_result(gp.gp_camera_new())
    gp.check_result(gp.gp_camera_init(camera))
    # required configuration will depend on camera type!
    print('Checking camera config')
    # get configuration tree
    config = gp.check_result(gp.gp_camera_get_config(camera))
    # find the image format config item
    # camera dependent - 'imageformat' is 'imagequality' on some
    OK, image_format = gp.gp_widget_get_child_by_name(config, 'imageformat')
    if OK >= gp.GP_OK:
        # get current setting
        value = gp.check_result(gp.gp_widget_get_value(image_format))
        # make sure it's not raw
        if 'raw' in value.lower():
            print('Cannot preview raw images')
            return 1
    # find the capture size class config item