python tkinter如何将键绑定到按钮

编程新手,特别是python和tKinter.如何创建一种方法将键“s”绑定到按钮或功能锐化？任何帮助都是极好的.

from Tkinter import *
from PIL import Image,ImageTk,ImageFilter,ImageEnhance

class Application(Frame):
    def __init__(self,master=None):
        Frame.__init__(self,master)
        master.wm_title("Image examples")
        self.pack()
        self.createWidgets()

def createWidgets(self):
    self.img = Image.open("lineage.jpg")
    self.photo1 = ImageTk.PhotoImage(self.img.convert("RGB"))
    self.label1 = Label(self,image=self.photo1)
    self.label1.grid(row=0,column=0,padx=5,pady=5,rowspan=10)

    self.photo2 = ImageTk.PhotoImage(self.img.convert("RGB"))
    self.label2 = Label(self,image=self.photo2)
    self.label2.grid(row=0,column=1,rowspan=10)

    button5 = Button(self,text="Sharpen",command=self.sharpen)
    button5.grid(row=4,column= 2,sticky = N)

def sharpen(self):
    img2 = self.img.filter(ImageFilter.SHARPEN)
    self.photo2 = ImageTk.PhotoImage(img2)
    self.label2 = Label(self,rowspan=10)