What is the Pythonic way to implement a simple FSM?

Question

Yesterday I had to parse a very simple binary data file - the rule is, look for two bytes in a row that are both 0xAA, then the next byte will be a length byte, then skip 9 byte

Answer 1

I suggest checking out chapter 4 of Text Processing in Python by David Mertz. He implements a state machine class in Python that is very elegant.