auto save

whiles3.py

+#关卡3  重复执行限制错误次数
+i=3
+while True:    
+	if i>0:
+		name = input("请输入用户名:")
+		password = input("请输入密码:")
+		i-=1
+		if name == username and password == userpassword:
+			print("登录成功!")
+			break
+		if name != username:
+			print("用户名错误,请重新输入!")
+			 
+		if password != userpassword:
+			print("密码输入有误,请重新输入!")
+		print("你有"+str(i)+"次机会")
+     else:
+	    print("欢迎下次再来贝尔编程")
+        exit; 	 
+			
+print("欢迎来到贝尔编程!")