auto save

my_app.py

 import tkinter
 
 def login_to_reg():    # 登录界面转注册界面
-    pass
+    app_login.root.destroy()
+    global app_reg
+    app_reg = My_register()
+    app_reg.show()
 
 def reg_to_login():   # 注册界面转登录界面
-    pass
+    app_reg.root.destroy()
+    global app_login
+    app_login = My_login()
+    app_login.show()
 
 def register():     # 注册验证
     pass
@@ -43,11 +49,10 @@ class My_login():       # 登录窗口
         button1 = tkinter.Button(self.root, text='登录', bg="lightblue",
                   fg="black", width=15, command=login)
         button1.place(x=60, y=220)
-        button1 = tkinter.Button(self.root, text='注册', bg="lightgreen",
+        button2 = tkinter.Button(self.root, text='注册', bg="lightgreen",
                   fg="black", width=15, command=login_to_reg)
-        button1.place(x=230, y=220)
-        # 进入消息循环，监听事件
-        self.root.mainloop()
+        button2.place(x=230, y=220)
+        self.root.mainloop()    # 进入消息循环，监听事件
 
     def get_input(self):      # 获取输入的用户名、密码
         self.name = self.e1.get()
@@ -91,9 +96,9 @@ class My_register():        # 注册窗口
         button1 = tkinter.Button(self.root, text='提交', bg="lightblue",
                   width=15,command=register)
         button1.place(x=230, y=250)
-        button1 = tkinter.Button(self.root, text='取消', bg="lightgreen",
+        button2 = tkinter.Button(self.root, text='取消', bg="lightgreen",
                   width=15, command=reg_to_login)
-        button1.place(x=80, y=250)
+        button2.place(x=80, y=250)
         # 进入消息循环
         self.root.mainloop()