lambda函数用于排序以及字典值的求和
data = input() # 课程名 考分
d = {}
while data:
data = data.split()
d[data[0]] = int(data[1]) #注意data[1]是字符串类型，不转换为int类型无法对成绩排序
data = input()
li = list(d.items())
li.sort(key = lambda x:x[1],reverse=True) #匿名函数的正确写法，类似于字典key:values的写法
max_c = li[0][0]
max_s = li[0][1]
min_c = li[-1][0]
min_s = li[-1][1]
# 注意对字典的values求和时是sum(d.values())，直接使用d.values会报错
print("最高分课程是{}{}, 最低分课程是{}{}, 平均分是{:.2f}".format(max_c,max_s,min_c,min_s,sum(d.values())/len(d)))
参考代码是对字典进行遍历然后求和
data = input()
d = {}
while data:
t = data.split()
d[t[0]] = int(t[1])
data = input()
ls = list(d.items())
ls.sort(key=lambda x: x[1], reverse=True)
s1, g1 = ls[0]
s2, g2 = ls[len(ls) - 1]
sum = 0
for i in d.values():
sum = sum + int(i)
avg = sum/len(ls)
print("最高分课程是{}{}, 最低分课程是{}{}, 平均分是{:.2f}".format(s1, g1, s2, g2, avg)
