How to interrupt threading timer?

Question

I am trying to interupt a timer in python and cannot seem to figure out why this is not working. I am expecting "false" to be printed from the last line?

import time
import threading

def API_Post():
    print("api post")

def sensor_timer():
    print("running timer")

def read_sensor():
    recoatCount = 0
    checkInTime = 5
    t = threading.Timer(checkInTime, sensor_timer)
    print(t.isAlive()) #expecting false
    t.start()
    print(t.isAlive()) #expecting True
    t.cancel()
    print(t.isAlive()) #expecting false


thread1 = threading.Thread(target=read_sensor)
thread1.start()

Answer 1

Timer is a subclass of the Thread with simple implementation. It waits the provided time by subscribing to the event finished. You need to use join on timer to guarantie that thread is actually finished:

def read_sensor():
   recoatCount = 0
   checkInTime = 5
   t = threading.Timer(checkInTime, sensor_timer)
   print(t.isAlive()) #expecting false
   t.start()
   print(t.isAlive()) #expecting True
   t.cancel()
   t.join()
   print(t.isAlive()) #expecting false