以Python为语言开发一个反应时间窗口

    import tkinter as tk
    import time
    import random
    import datetime
    Count = 0
    def change_color(event = None):
    # change background color
    Time = random.randint(10,14)
    global Count
    if Count == 0:
        time.sleep(2)
        v1.set(datetime.datetime.now())
        canvas.config(bg = 'red')
        Count = 1
    else:
        Count = 0
        time.sleep(2)
        v1.set(datetime.datetime.now())
        canvas.config(bg = 'green')
    
    def Reaction_time():
    temp_1 = datetime.datetime.strptime(p1.get(), "%Y-%m-%d %H:%M:%S.