Python练习一

1.实现1-100的所有的和

方法一：

sum = 0

for i in xrange(1,101):

sum += i

print sum

方法二：

num = reduce(lambda x,y:x+y,xrange(1,101))

print num

方法三：

num = sum(xrange(1,101))

print num

2.实现1-500所有奇数的和

方法一：

sum = 0

for i in xrange(1,501):

if(i % 2 == 1):

sum += i

print sum

方法二：

sum = 0

for j in xrange(1,501,2):

sum += j

print sum

3.求1+ 2! + 3! + 4! + ……20！的和

方法一：

sum = 0

sum1 = 1

for i in xrange(1,21):

sum1 *= i

sum += sum1

print sum

方法二：

import math

sum = 0

for i in xrange(1,21):

sum += math.factorial(i)

print sum

方法三：

sum = 0

sum1 = 1

for x in xrange(1,21):

for y in xrange(x,x+1):

sum1 *= y

sum += sum1

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]

方法一：

list = [2,32,43,453,54,6,576,5,7,6,8,78,7,89]

print(sorted(list))

方法二：

list = [2,32,43,453,54,6,576,5,7,6,8,78,7,89]

list.sort()

print(list)