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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def display_index(config):
 """Open index in web browser. Parameters config : Config Configuration settings. Raises ------ FileNotFoundError If index file doesn't exist. """

    browser = config["web browser"].lower()
    data_dir = Path(config["data dir"])
    if browser in webbrowser._browsers:
        b = webbrowser.get(browser)
    else:
        if browser != "default":
            logger.warning(
                "Couldn't find '%s' browser. Falling back to default.", browser
            )
        b = webbrowser.get()
    index_file = data_dir.joinpath("index.html")
    if not index_file.exists():
        logger.error("File doesn't exist: %s", index_file.as_posix())
        raise FileNotFoundError("Index file doesn't exist")
    else:
        logger.info("Opening %s in '%s'", index_file.as_posix(), b.name)
        b.open(index_file.as_uri())