save project

diy.py

+username="pytuon"
+userpassword="123456"
+while True:
+    a=input("输入你的账户")
+    b=input("输入你的密码")
+    if a==username and b==userpassword:
+        print("登录成功!")
+        break
+    elif a !=username:
+        print("用户名不存在,重新登录！")
+    elif b !=userpassword:
+        print("密码有误，重新登录！")
+print("欢迎来到贝尔编程！")    
+            
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