save project

diy1.py

 username = "python"   
 userpassword = "123456"
+i=3
 while Ture:
-    name=input("请输入用户名：")
-    password=input("请输入密码：")
-    if name == username and password == userpassword:
-        print("登陆成功")
-        break
-    elif name!=username:
-        print("用户名不存在，请重新输入！")
-    else password!=userpassword:
-        print("用密码错误！请重新输入")
+    if i>0
+        name=input("请输入用户名：")
+        password=input("请输入密码：")
+        if name == username and password == userpassword:
+            print("登陆成功")
+            i-=1
+            break
+        if name!=username:
+            print("用户名不存在，请重新输入！")
+            continue
+        if password!=userpassword:
+            print("用密码错误！请重新输入")
+            exit()
 print("欢迎来到贝尔编程！")