save project

diy2.py

 username = "python"
 username = "python"
 userpassword = "123456"
 userpassword = "123456"
+cishu = 3
 while True:
 while True:
-    name = input("请输入用户名:")
-    password = input("请输入密码:")
-    if name == username and password == userpassword:
-        print("登录成功!")
-        print("欢迎来到贝尔编程!")
-        break
+    if cishu >0:
+        name = input("请输入用户名:")
+        password = input("请输入密码:")
+        cishu -=1 # cishu = cishu - 1
+        if name == username and password == userpassword:
+            print("登录成功!")
+            print("欢迎来到贝尔编程!")
+            break
+        elif name != username:
+            print("账号不存在，请重输!")
+            print("你还有"+str(cishu)+"次输入的机会")
+            continue
+        elif password != password:
+            print("密码不正确，请重输!")
+            print("你还有"+str(cishu)+"次输入的机会")
+        else:
+            print("用户名和密码错误!请重新输入")
+            print("你还有"+str(cishu)+"次输入的机会")
     else:
     else:
-        print("用户名和密码错误!请重新输入")
+        print("你的输入次数已用完！")