Python multiprocessing question! (Correction)

import time
from multiprocessing import Process


class Test:
    def __init__(self):
        self.queue = []
        self.end = 0

    def write(self):
        for i in range(20):
            self.queue.append((i, i+1) #Add data to queue
            # Modify the end value so that it can be broken after the input is completed until the end
            if i == 19:
                self.end = 1    


    def read(self):
        while True:
            if not self.queue: # Sleep for 1 second if queue is empty
                time.sleep(1)   
            else:
                ans = self.queue.pop(0) #Reads when data is present in the queue
                print(ans[1]) 
           # If there is no data in the queue and the end value is 1, exit
            if not self.queue and self.end == 1: 
                break


if __name__ == '__main__':
    tester = Test() #ObjectCreation

    p1 = Process (target=testter.write, args=()) #writeProcess
    p1.start()

    p2 = Process (target=testter.read, args=()) #readprocess
    p2.start()

    p1.join()
    p2.join()