1.实现用户输入用户名和密码，当用户名为seven且密码为123时，显示登陆成功，否则登陆失败！
2.输入10个同学名字和一门功课成绩的字典，计算成绩的最高分、最低分、平均分.
1username = input("请输入用户名：")
pwd = input("请输入密码：")
if username == "seven" and pwd == "123":
print("登录成功");
else:
print("登录失败")
2
dic1 = {}
for i in range(10):
sname = input("请输入姓名：")
score = int(input("请输入成绩："))
dic1[sname] = score
sum = 0
max = 0
min = 0
for i in dic1.values():
sum = sum + i
if i > max: max = i
if i < min: i = min
print(dic1)
print(max, min, sum / 10)