python实现的简单窗口倒计时界面实例

# Countdown using Tkinter 
from Tkinter import *
import time
import tkMessageBox
class App:
 def __init__(self,master):
  frame = Frame(master)
  frame.pack()
  self.entryWidget = Entry(frame)
  self.entryWidget["width"] = 15
  self.entryWidget.pack(side=LEFT)
  self.hi_there = Button(frame,text="Start",command=self.start)
  self.hi_there.pack(side=LEFT)
  self.button = Button(frame,text="QUIT",fg="red",command=frame.quit)
  self.button.pack(side=LEFT)
 def start(self):
  text = self.entryWidget.get().strip()
  if text != "":
   num = int(text)
   self.countDown(num)
 def countDown(self,seconds):
  lbl1.config(bg='yellow')
  lbl1.config(height=3,font=('times',20,'bold'))
  for k in range(seconds,-1):
   lbl1["text"] = k
   root.update()
   time.sleep(1)
  lbl1.config(bg='red')
  lbl1.config(fg='white')
  lbl1["text"] = "Time up!"
  tkMessageBox.showinfo("Time up!","Time up!")
 def GetSource():
  get_window = Tkinter.Toplevel(root)
  get_window.title('Source File?')
  Tkinter.Entry(get_window,width=30,textvariable=source).pack()
  Tkinter.Button(get_window,text="Change",command=lambda: update_specs()).pack()
root = Tk()
root.title("Countdown")
lbl1 = Label()
lbl1.pack(fill=BOTH,expand=1)
app = App(root)
root.mainloop()