为另一个Python程序创建UI如何在tkinter中为Python 3制作打印标签？

我正在为另一个python程序创建一个UI，它实际上只是为项目提供了一个交互式组件。目标是要有一个特定的标签，可以从按钮运行的python程序中更新（打印语句）。这就是我在用户界面中编写的内容...

---

import tkinter as ttk
import subprocess
import sys
import time
import os
import tkinter.font as font
from tkinter.ttk import *

app = ttk.Tk()

app.geometry("400x400")
app.configure(bg='gray')

photo = ttk.PhotoImage(file=r"C:\Users\ex\ex_button_active.png")
myFont = font.Font(family='Helvetica',size=20,weight='normal')

ttk.Label(app,text='Ex',bg='gray',font=(
    'Verdana',15)).pack(side=ttk.TOP,pady=10)
app.iconbitmap(r'C:\Users\ex\ex_icon.ico')


def ex_activation():
    global pro
    print("Running program!")
    pro = subprocess.Popen("python programex.py",shell=True)


def ex_stop():
    global pro
    print("Stopping Program... Please Wait!")
    os.kill(pro.pid,0)


ex_activation_button = ttk.Button(app,bg='black',image=photo,width=120,height=120,command=ex_activation)

ex_stop_button = ttk.Button(app,bg='Gray',text='Stop Program',width=12,command=ex_stop,height=3)

ex_stop_button['font'] = myFont

app.title("Ex")
ex_activation_button.pack(side=ttk.TOP)
ex_stop_button.pack(side=ttk.LEFT)

# app.mainloop()
while True:
    try:
        app.update()
        app.update_idletasks()
    except KeyboardInterrupt:
        pass

---

如果有人对如何在代码中实现This StackOverflow Post有任何想法，我将非常感谢您的帮助和支持。

编辑acw1668这些是我运行的一些测试，并且在Pycharm运行窗口而不是UI中得到了一些奇怪的数字。

Running program!
3528
Stopping Program 3528 ... Please Wait!
monitor done
Running program!
144
Stopping Program 144 ... Please Wait!
monitor done
Running program!
14008
Stopping Program 14008 ... Please Wait!
monitor done
Running program!
21748
Stopping Program 21748 ... Please Wait!
monitor done