在Python tkinter中实现了开始,如何跳出循环 求大神给看看
import tkinter.filedialog
from tkinter import *
import random
import time
yaohao_window = tkinter.Tk()
yaohao_window.geometry('600x600')
yaohao_window.title('摇号系统')
text = StringVar()
text.set("0")
a = StringVar()
a.set("1")
def k( ):
text.set(str(random.randint(1, 50)))
time.sleep(1)
yaohao_window.update()
k( )
def g( ):
a="2"
b = Button(yaohao_window, text='开始', font=('KaiTi', 36, 'bold'), bd=2, width=4, command=k)
b.pack()
b2 = Button(yaohao_window, text='结束', font=('KaiTi', 36, 'bold'), bd=2, width=4, command=g)
b2.pack()
l = Label(yaohao_window, bg='yellow', font=('KaiTi', 10, 'bold'), width=40, textvariable=text, )
l.pack(side=BOTTOM, expand=YES, fill=BOTH)
yaohao_window.mainloop()