def get_resnumbers(args):
    'Return residue-numbers as list-of-integers'
    resids = []
    for resid in args:
        try:
            resids.append(int(resid))
        except ValueError:
            print('ValueError with ', resid, ' expected: Integer')
            usage()
    if (len(resids) > 7):
        print('FATAL:')
        print('You ask me to mutate more than 7 residues at one time.')
        print('This is NOT IMPLEMENTED...    ...probably a BAD IDEA :')
        print('This is a bad idea, because we grow with LIBRARY^{#RES}!')
        print('In your case ', len(LIB), '^', len(LIB), '=', (len(LIB) ** len(resids)), '!')
        usage()
    return resids
Return residue-numbers as list-of-integers
def get_resnumbers(args):
    
    resids = []
    for resid in args:
        try:
            resids.append(int(resid))
        except ValueError:
            print('ValueError with ', resid, ' expected: Integer')
            usage()
    if (len(resids) > 7):
        print('FATAL:')
        print('You ask me to mutate more than 7 residues at one time.')
        print('This is NOT IMPLEMENTED...    ...probably a BAD IDEA :')
        print('This is a bad idea, because we grow with LIBRARY^{#RES}!')
        print('In your case ', len(LIB), '^', len(LIB), '=', (len(LIB) ** len(resids)), '!')
        usage()
    return resids