import dis # This function will return False due to short circuit. def test_1(): return True != True in [False, False] # This function will return True. def test_2(): return True != (True in [False, False]) # This function will return True. def test_3(): return (True != True) in [False, False] print('Offending bytecode:') dis.dis(test_1) print('Comparison 1:') dis.dis(test_2) print('Comparison 2:') dis.dis(test_3) print('Results:', test_1(), test_2(), test_3(), sep='\n\t')