util.py

def phasing(phaser_attr):
   def phaser(f):
      @wraps(f)
      def wrapper(self, *args, **kwargs):
         state = eval("self.%s" % phaser_attr)
         if hasattr(f, "phases") and state in f.phases:
            return f.phases[state](self, *args, **kwargs)
         elif hasattr(f, "phase_points"):
            points = [pt for pt in f.phase_points if pt <= state]
            if len(points) > 0:
               return f.phase_points[max(points)](self, *args, **kwargs)
            else:
               return f(self, *args, **kwargs)
         else:
            return f(self, *args, **kwargs)
      wrapper.f = f

      def phase_to(*states):
         def phase_to_er(this_phase_f):
            if not hasattr(wrapper.f, "phases"):
               wrapper.f.phases = {}
            for state in states:
               wrapper.f.phases[state] = this_phase_f
            return wrapper
         return phase_to_er
      wrapper.phase_to = phase_to

      def phase_after(state):
         def phase_after_er(this_phase_f):
            if not hasattr(wrapper.f, "phase_points"):
               wrapper.f.phase_points = {}
            wrapper.f.phase_points[state] = this_phase_f
            return wrapper
         return phase_after_er
      wrapper.phase_after = phase_after

      return wrapper
   return phaser