def f1():

a=lbx.curselection()

lbx.delete(a)

def f2():

lbx.delete(0,END)

def f3():

lbx.delete(0,END)

LoadData()

f=Label(root)

f.grid(row=2,column=0)

b1=Button(f,text="删除",command=f1)

b1.grid(row=0,column=0,padx=8)

b2=Button(f,text="清空",command=f2)

b2.grid(row=0,column=1,padx=8)

b3=Button(f,text="还原",command=f3)

b3.grid(row=0,column=2,padx=8)