python使用tkinter实现屏幕中间倒计时

import time
from tkinter import Tk,Label

class TimeShow():#实现倒计时
  
  def __init__(self,time_show=5):
    self.timeShowWin=Tk()
    self.timeShowWin.overrideredirect(True)
    self.timeShowWin.attributes('-alpha',1)
    self.timeShowWin.attributes('-topmost',True)
    self.timeShowWin.attributes('-transparentcolor','black')  
    self.time_show = time_show
    self.time_label=Label(self.timeShowWin,text='倒计时{}秒'.format(self.time_show),font=('楷体',25),fg='red',bg='black')
    self.time_label.pack(fill='x',anchor='center')
    self.timeShowWin.geometry('+'+str(int(self.timeShowWin.winfo_screenwidth()/2))+'+'+str(125))
    self.timeShowWin.after(1,self.show)

  def show(self):
    while self.time_show >= 0:
      print('time_label={}'.format(self.time_label))
      self.time_label['text']= '倒计时{}秒'.format(self.time_show)
      self.timeShowWin.update()
      self.time_show -= 1
      time.sleep(1)
    self.timeShowWin.destroy()
  
  def start(self):
    print('ok')
    self.timeShowWin.mainloop()
    

if __name__ == '__main__':
  a=TimeShow(10)
  a.start()