代码如下：

from tkinter import *import webbrowserroot = Tk()w = Canvas(root,width=400,height=200)w.pack()def paint(event):    x1,y1 = (event.x-1),(event.y-1)    x2,y2 = (event.x+1),(event.y+1)    w.create_oval(x1,y1,x2,y2,fill="red")w.bind("
     
      ",paint)Label(root,text="使用鼠标左键开始画图").pack(side=BOTTOM)mainloop()
     

运行截图：