各位老哥，萌新想实现一个登记记录本的小工具

from tkinter import *
root = Tk()
root.geometry("240x320")
root.title(".....")
class Login:
def __init__(self):
self.shuru = Entry(root, font=("宋体", 15))
self.txt = Text(root, font=("宋体", 15))
self.anniu = Button(root, text="login", font=("宋体", 15), command=self.dengji)
def start(self):
self.shuru.place(relx=0.3, rely=0.1, relwidth=0.3, relheight=0.1)
self.txt.place(relx=0.3, rely=0.5, relwidth=0.3, relheight=0.3)
self.anniu.place(relx=0.3, rely=0.25, relwidth=0.3, relheight=0.1)
root.mainloop()
def dengji(self):
mz = self.shuru.get()
print(">>>>> ok%s:" % mz)
self.txt.insert(END, mz+"\n")
self.shuru.delete(0, END)
return
l = Login()
l.start()