def Add_Filter(vcf):
    """Adds filter info based on whether a variant is a snp and its predicted
       truth value

    Parameters
    ----------
    vcf : DataFrame
        vcf file with variants of interest

    Returns
    -------
    str
        'EVF_SNP' if the variant is a SNP and predicted False
        'EVF_IND' if the variant is an InDel and predicted False
        '.' for all others
    """
    if vcf['Is_SNP'] == 1 and vcf['Predict'] == 0:
        return 'EVF_SNP'
    elif vcf['Is_SNP'] == 0 and vcf['Predict'] == 0:
        return 'EVF_IND'
    else:
        return '.'
