auto save

my_app.py

 import tkinter
+from tkinter import messagebox 
+
+with open("use.txt", "r", encoding="utf-8") as f:
+    info = f.read()
+    users = json.load(info)
 
 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
+    name,password1,password2 = app_reg.get_input()
+    if name =="" or password1=="" or password2=="":
+        messagebox.showwarning("警告","请填写完整的注册资料")
+    elif name in users:
+        messagebox.showwarning("错误"，"用户名已存在！")
+    elif password1 != password2:
+        messagebox.showwarning("错误", "两次密码不一致！")
+    else:
+        users[name] = password1
 
 def login():    # 登录验证
     pass    
@@ -104,4 +124,4 @@ class My_register():        # 注册窗口
         return self.name, self.password1, self.password2
 
 app_login = My_login()
-app_login.show()
\ No newline at end of file
+app_login.show() 
\ No newline at end of file