如果发生事件，则在Python中唤醒一个线程

Question

I know questions like this have already been asked, so in a sense, this is a duplicate. However, I've looked at many of those questions, and numerous websites, and I still can't figure out how to do what the title of this question says. This is what I'm trying to accomplish, more specifically:

One thread, t_sensors , reads values from a sensor, and after it does so, goes to sleep for refresh_rate amount of seconds. This might be a few hours, so during this time it could get a request to read values from the sensor again. This request comes from the thread t_checker , which checks for data in a Firebase database, and based on the data, chooses whether or not to wake up t_sensors .

def start_sensors(self):
     # do some stuff...
     # refreshes every refresh_rate secs
     refresh_rate = firebase_root.get('/settings', 'refreshRate')
     condition.wait(refresh_rate)

 def check_for_plants(self):
     while True:
         modded_plants = firebase_root.get('/modifiedPlants', '')
         print(modded_plants)
         for plant, properties in modded_plants.items():
             print properties['status']
             if properties['status'] == 'modified':
                 condition.notify()
                 print("Notified")

 condition = threading.Condition()
 t_sensors = threading.Thread(target=start_sensors, args=(condition,))
 t_checker = threading.Thread(target=check_for_plants, args=(condition,))
 condition.acquire()
 t_sensors.start()
 t_checker.start()

I know I'm not using conditions correctly, at all, but I'm really not sure where I should even start fixing the problem. I'd really, really appreciate your help.

Answer 1

In the end, I chose to avoid threads altogether... I found they were unnecessary. Instead, I passed the value of refresh_rate to check_for_plants() from start_sensors() , and then it slept in increments of 2 seconds until the time was up, or called start_sensors() if an event occurred. Thank you so much for all the help!