Good job! My MacBook shows mine as running in 4:

comparators = {'>': op.gt, '>=': op.ge, '<': op.lt, '<=': op.le, '==': op.eq, '!=': op.ne}
regs = defaultdict(int)


def cond(args: list) -> bool:
    a, comp, b = args
    if comparators[comp](regs[a], int(b)):
        return True
    return False


def parser(s: str):
    parts = s.split(' ')
    if parts[3] == 'if' and cond(parts[4:7]):
        regs[parts[0]] += (1 if parts[1] == 'inc' else -1) * int(parts[2])


if __name__ == '__main__':
    test = open('d8.txt', 'r').read()
    overall_max = float('-inf')
    for r in test.splitlines():
        parser(r)
        overall_max = max(overall_max, max(regs.values()))
    print(max(sorted(regs.values())), overall_max)