原理根据 https://blog.quarkslab.com/building-an-obfuscated-python-interpreter-we-need-more-opcodes.html
增加了3条指令用于混淆，比较2.7.9源码就可以看到对应改动
./python test_op.py
2 0 <148> 1
3 COMPARE_OP 4 (>)
6 POP_JUMP_IF_FALSE 31
9 LOAD_GLOBAL 0 (fib)
12 <148> 1
15 BINARY_SUBTRACT
16 CALL_FUNCTION 1
19 LOAD_GLOBAL 0 (fib)
22 <148> 2
25 BINARY_SUBTRACT
26 CALL_FUNCTION 1
29 BINARY_ADD
30 RETURN_VALUE
>> 31 <149> 0
6 0 <148> 1
3 BINARY_ADD
4 STORE_FAST 1 (b)
8 7 <149> 1 11 0 <150> 0 14 0 LOAD_GLOBAL 0 (True) 3 RETURN_VALUE
看到修改结果