def p_list_andnot(self, p):
        p[0] = p[1][set(p[1].index)-set(p[3].index)]
Returns true if received `secret` matches expected secret for form_instance.
dataset/ETHPy150Open neurosynth/neurosynth/neurosynth/base/lexparser.py/Parser.p_list_andnot--crossover with--dataset/ETHPy150Open spookylukey/django-paypal/paypal/standard/helpers.py/check_secret