OOP Statemachine

state.py

class Context():
    def __init__(self):
        self.result = []
        self.current = {}
        self.lastValue = 0

    def setBeginValue(self, value):
        self.current['beginValue'] = value

    def buildResult(self):
        if self.current:
            self.current['endValue'] = self.lastValue
            self.result.append(self.current)
            self.current = {}

class StateMachine():
    def __init__(self):
        self.state = BeginState
        self.context = Context()

    def __getattr__(self, attr):
        if attr in ['begin', 'middle', 'end']:
            method = getattr(self.state, attr)
            def caller(*args, **kwargs):
                self.state = method(self.context, *args, **kwargs)
                self.context.lastValue = args[0]
            return caller
        else:
            raise AttributeError(attr)

    def result(self):
        if self.state == EndState:
            self.context.buildResult()
        return self.context.result

class State():
    @classmethod
    def begin(cls, context, index, value):
        return cls

    @classmethod
    def middle(cls, context, index, value):
        return cls

    @classmethod
    def end(cls, context, index, value):
        return cls

class BeginState(State):
    @classmethod
    def begin(cls, context, index, value):
        context.setBeginValue(index)
        return MiddleState

class MiddleState(State):
    @classmethod
    def end(cls, context, index, value):
        return EndState

class EndState(State):
    @classmethod
    def begin(cls, context, index, value):
        context.buildResult()
        return BeginState.begin(context, index, value)

    @classmethod
    def middle(cls, context, index, value):
        context.buildResult()
        return BeginState

machine = StateMachine()
mapping = {
    1: "begin",
    0: "middle",
    -1: "end"
}

for index, value in enumerate(lst):
    method_name = mapping[value]
    method = getattr(machine, method_name)
    method(index, value)

from pprint import pprint
pprint(machine.result())