我正在学习React，并且正在尝试使用componentDidmount。 但是由于某种原因，此方法会使所有应用程序崩溃。

我正在使用Visual Studio代码，它将所有componentDidmount涂成红色。 我得到的错误是：

  

import simpy from simpy.util import start_delayed # import numpy.random from collections import deque,namedtuple from numpy import random NUM_INT = 3 ARRIVAL_TIME_MEAN = 1.1 TRIP_LENGTH = 4 GREEN_TIME = 3.0 RED_TIME = 3.0 class Simulation(object): def __init__(self,env): self.env = env self.intersections = [Intersection(env,i) for i in range(NUM_INT)] for (i,intersection) in enumerate(self.intersections): intersection.set_next_intersection(self.intersections[(i+1)%NUM_INT]) self.env.process(self.light()) self.env.process(self.arrivals()) def arrivals(self): while True: yield self.env.timeout(random.exponential(ARRIVAL_TIME_MEAN)) intersection = random.choice(self.intersections) intersection.receive(TRIP_LENGTH) def light(self): while True: for intersection in self.intersections: intersection.start_departing() yield self.env.timeout(GREEN_TIME) for intersection in self.intersections: intersection.turn_red() yield env.timeout(RED_TIME) class Intersection(object): def __init__(self,env,index): self.index = index self.queue = deque() self.env = env self.start_departing() def set_next_intersection(self,intersection): self.next_intersection = intersection def start_departing(self): self.is_departing = True self.action = env.process(self.departure()) def turn_red(self): if self.is_departing: self.is_departing = False self.action.interrupt('red light') def receive(self,car): self.queue.append(car) if not self.is_departing: self.start_departing() def departure(self): while True: try: if len(self.queue)==0: self.is_departing = False self.env.exit('no more cars in %d'%self.index) else: yield self.env.timeout(1.0) car = self.queue.popleft() car = car - 1 if car > 0: self.next_intersection.receive(car) except simpy.Interrupt as i: print('interrupted by',i.cause) env = simpy.Environment() sim = Simulation(env) env.run(until=15.0)