def sample_name_to_fasta_path(sample_name, dest_dir):
    """
    Convert sample name like '70_HOW9' to a file path to save the .fasta
    file in

    :param sample_name: a string specifying a sample name, typically like
     '70_HOW9'
    :param dest_dir: directory to save to
    :return: file path string
    """
    return dest_dir + '/fasta_files/' + sample_name + '.fasta'