def get_fprimer_percent_aln(fprimer, percent_alignment):
    """
    Gets the len of the fprimer and calculates minimum percent alignment
    based on user input of maximum alignment between 2 primers allowed.
    See percent alignment help for info.
    Args:
        fprimer (str): the forward primer
    Returns:
        fp_len (int): user defined total number of bases to allowed to match.
    """
    fp_len = []
    for fseq in fprimer:
        f_len = len(fseq)
        min_dimer_alignment = int(f_len*(percent_alignment/100))
        fp_len.append(min_dimer_alignment)
    return fp_len