Subset the GRASP database on a specific phenotype.
    
    Parameters
    ----------
    fn : str
        Path to GRASP database file.

    pheno : str
        Phenotype to extract from database.

    out : sttr
        Path to output file for subset of GRASP database.

def make_grasp_phenotype_file(fn, pheno, out):
    """
    Subset the GRASP database on a specific phenotype.
    
    Parameters
    ----------
    fn : str
        Path to GRASP database file.

    pheno : str
        Phenotype to extract from database.

    out : sttr
        Path to output file for subset of GRASP database.
    """
    import subprocess
    c = 'awk -F "\\t" \'NR == 1 || $12 == "{}" \' {} > {}'.format(
        pheno.replace("'", '\\x27'), fn, out)
    subprocess.check_call(c, shell=True)