练习题1

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time     : 2017/10/26 21:11
# @Author   : keshen
# @File     : test1.py
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# 1. 实现1-100的所有的和
sum = 0
for i in xrange(1, 101):
    sum += i
print(sum)
# 2. 实现1-500所有奇数的和
sum = 0
for i in xrange(1, 501):
    if i%2 != 0:
        sum += i
print(sum)
# 3. 求1+ 2! + 3! + 4! + ……20！的和
# 方法一：
def fac(x):
    if x <= 1:
        return 1
    else:
        return fac(x-1) * x
sum = 0
for i in xrange(1, 21):
    sum += fac(i)
print(sum)
# 方法二：
import math
sum = 0
for i in xrange(1, 21):
    sum += math.factorial(i)
print(sum)
# 4.对指定一个list进行排序[2,32,43,453,54,6,576,5,7,6,8,78,7,89]
l = [2,32,43,453,54,6,576,5,7,6,8,78,7,89]
print(l)
print(sorted(l))