def openfile(self):
  p1=END
  oname=askopenfilename(filetypes=[("文本文档","*.txt")])
  if oname:
   for line in fileinput.input(oname):
    self.st.insert(p1,line)
   self.t.title(oname)
def savefile(self):
  sname=asksaveasfilename()
  if sname:
   ofp=open(sname,"w")
   ofp.write(self.st.get(1.0,END))
   ofp.flush()
   ofp.close()
   self.t.title(sname)

这是菜单当中的打开命令的代码，如何使其同时实现对txt和doc文件的阅读，或者改为对doc的阅读