使用事件在线程中循环时，如何修复Window对象不具有_stop_thread属性？

Question

I am writing a program that automates a certain task while the user is away. The program has a GUI with Tkinter so that the user can start and stop execution at any time. To control the execution of repetitive tasks I am using a loop which executes when a threading event is not set. The constructor of the Window class shown below initializes the threading event in a variable called stop_thread but when I use it in a while loop inside my threaded function to determine whether to execute the task I get an AttributeError saying the the Window class does not have stop_thread.

My current version of Python is 3.7.4 and I have tested the program in both IDLE and PyCharm both give the same error.

I have uploaded part of my code below

from tkinter import *
import random
import time
from threading import Thread,Event

class Window(Frame):

    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.master = master
        self.init_window()                  
        self.backgroundThread=Thread(name='bgTask',
                              target=self.s_i())
        self.stop_thread = Event()

    def init_window(self):
        self.master.title = "Test"
        self.grid()
        text = Label(self, text="Test")
        text.config(font=('Arial', 20, 'bold'))
        text.grid(row=0, column=0, columnspan=3, sticky="nsew")

        start=Button(self,text="Start",command=lambda:self.start())
        start.grid(row=1,column=0,sticky="nsew")

        stop = Button(self, text="Stop", command=lambda: self.stop())
        stop.grid(row=1, column=2,sticky="nsew")

        for i in range(3):
            self.columnconfigure(i,weight=1)

    def s_i(self):
        print('Test has started')
        while not self.stop_thread.isSet():
            time.sleep(15)
            #do something
            print("Hi")
            time.sleep(0.1)
            #do something
            print("Hi")
            time.sleep(0.1)
            #do something
            print("Hi")
            time.sleep(0.1)
            #do something
            print("Hi")
            delay = round(random.uniform(1, 10), 2)
            sleep_time = delay * 60
            time.sleep(sleep_time)

    def start(self):
        self.backgroundThread.start()

    def stop(self):
        self.stop_thread.set()







root = Tk()
root.columnconfigure(0,weight=1)
app = Window(root)
root.mainloop()

I expect the code to run and when I hit start in the window the task will run repetitively until I hit stop. Instead I am getting the following error:

Traceback (most recent call last):
  File "/Users/Steven/Desktop/Projects/Python/SITG/SITG.py", line   63, in <module>
app = Window(root)
  File "/Users/Steven/Desktop/Projects/Python/SITG/SITG.py", line 12, in __init__
self.backgroundThread = Thread(name='bgTask',target=self.s_i())
  File "/Users/Steven/Desktop/Projects/Python/SITG/SITG.py", line 32, in s_i
while not self.stop_thread.isSet():
AttributeError: 'Window' object has no attribute 'stop_thread'

Answer 1

Your problem is in the __init__() function:

    self.backgroundThread=Thread(name='bgTask',
                          target=self.s_i())

You want target=self.si , identifying self.si as a function to be called later .

But instead you have target=self.si() , meaning the function is actually called now , and at that point self.stop_thread has not been defined yet.