gistfile1.py

class ActionManager(IOBase):
    def __init__(self, action, socket, finished_callback=None):
        self.action = action
        self.socket = socket
        self.finished_callback = finished_callback
        self.vars = {}
    
    def register(self, fdmanager):
        if self.action is None:
            return
        # It's an ugly hack, but sufficient for presentation purposes
        if isinstance(self.action, WriteAction):
            fdmanager.register_write(self.socket, self.callback)
        elif:
            fdmanager.register_read(self.socket, self.callback)

    def callback(self):
        self.action.run(self.socket, self.vars)
        self.action = self.action.next_action

        if self.action is None and self.finished_callback:
            self.finished_callback()