方法1：
1!/usr/bin/env python
2 # coding=utf-8
3
4 #产生一个列表，其中有40个元素，每个元素是0到100的一个随机整数
5 #如果这个列表中的数据代表着某个班级40人的分数，请计算成绩低于平均分的学生人数，并输出
6 #对上面的列表元素从大到小排序
7 import random
8 #导入random模块
9 lst_number = random.sample(range(0,100),40)
10 #利用range生成0到100的整数，然后调用random模块的sample方法在0到100中随机生成40个数字
11 print ‘随机数：‘,lst_number
12 sun = 0
13 mean = 0
14 for i in lst_number:
15 sun=sun+i
16 mean = sun /40
17 print ‘总和：‘,sun
18 print ‘平均值：‘,mean
19
20 score = []
21 for i in lst_number:
22 if i < mean:
23 score.append(i)
24 score.sort()
25 print ‘低于平均分的为：‘, score
[[email protected] pythonspace]# python lianxi2.py
随机数： [25, 35, 63, 56, 89, 16, 98, 51, 78, 59, 19, 4, 40, 50, 38, 79, 96, 23, 94, 29, 99, 93, 70, 13, 46, 54, 6, 39, 81, 90, 67, 62, 9, 57, 75, 27, 58, 86, 30, 92]
总和： 2196
平均值： 54
低于平均分的为： [4, 6, 9, 13, 16, 19, 23, 25, 27, 29, 30, 35, 38, 39, 40, 46, 50, 51]
方法2：
#!/usr/bin/env python
# coding=utf-8
from __future__ import division
import random score = [random.randint(0,100) for i in range(40)] #0到100之间，随机得到40个整数，组成列表
print score num = len(score) sum_score = sum(score) #对列表中的整数求和
ave_num = sum_score/num #计算平均数
less_ave = len([i for i in score if i<ave_num]) #将小于平均数的找出来，组成新的列表，并度量该列表的长度
print "the average score is:%.1f" % ave_num
print "There are %d students less than average." % less_ave
sorted_score = sorted(score, reverse=True) #对原列表排序
print sorted_score
[[email protected] pythonspace]# python lianxi2.py
[63, 76, 58, 33, 46, 72, 17, 52, 89, 58, 67, 79, 95, 52, 90, 43, 37, 20, 62, 72, 20, 50, 48, 59, 83, 27, 83, 55, 36, 95, 3, 6, 95, 83, 38, 11, 4, 94, 39, 34]
the average score is:53.0
There are 20 students less than average.
[95, 95, 95, 94, 90, 89, 83, 83, 83, 79, 76, 72, 72, 67, 63, 62, 59, 58, 58, 55, 52, 52, 50, 48, 46, 43, 39, 38, 37, 36, 34, 33, 27, 20, 20, 17, 11, 6, 4, 3]