def picard_header(file_col_list):
    """Extracts the command and date rows from a picard file that has been converted into a list of the columns."""

    # GATK picard stats files have a row in the files that includes the command used to make the file and a timestamp
    # the command was started. Both of these rows start with "# " with no other lines having this same pattern.
    # This step loops through each line looking for the pattern, removes it and returns the result.
    bam_headers = []
    for file_line in file_col_list:
        if file_line[0].startswith("# "):
            bam_headers.append(file_line[0].replace("# ", ""))

    return bam_headers