Creates a new file if the file name does not exists
    :param filename: the name of the file

def create_file(filename):
    """
    Creates a new file if the file name does not exists
    :param filename: the name of the file
    """

    expanded_filename = os.path.expanduser(os.path.expandvars(filename))
    if not os.path.exists(expanded_filename):
        open(expanded_filename, "a").close()