save project

my_app.py

 import tkinter
 from tkinter import messagebox
+import json
+with open("user.txt","r",encoding="utf-8") as f:
+    info = f.read()
+    users = json.loads(info)
 def login_to_reg():    # 登录界面转注册界面
     app_login.root.destroy()
     global app_reg
@@ -14,9 +18,13 @@ def reg_to_login():   # 注册界面转登录界面
     app_login.show()                      
 
 def register():     # 注册验证
-    name,password1,password2 == app_reg.get_input()
+    name,password1,password2 = app_reg.get_input()
     if name == "" or password1=="" or password2=="":
         messagebox.showwarning("警告","请填写完整信息")
+    elif name in users:
+        messagebox.showwarning("错误","用户已存在")
+    elif password1 != password2:
+        messagebox.showwarning("错误","两次密码输入不一致")
 def login():    # 登录验证
     pass