从任意长度的可迭代对象中分解元素

"""假设开设了一门课程，并决定在期末的考试成绩中去掉最高分和最低分，
只对中间剩下的成绩做平均统计"""
from functools import reduce


def drop_first_last(grade):
    grade.sort()
    first,*middle,last = grade
    a = reduce(lambda i,j:i+j,middle)  # lambda表达式做法
    # sum = 0
    # for i in middle:
        # sum += i
    # print(sum/len(middle))
    print(a/len(middle))


drop_first_last([90,100,60,88,92])


# 拆分操作的应用,可用*_表示不需要的变量
line = "chichung:*:-2:-2:Unprivileged User:/var/empty:/usr/bin"
uname,*_,homedir,sh = line.split(":")
print("\n")
print(uname)
print(homedir)
print(sh)