Python 练习实例24

最后更新于:2022-03-27 01:23:50

Python 练习实例24

Python 练习实例24 Python 100例

题目:有一分数序列:2/1,3/2,5/3,8/5,13/8,21/13…求出这个数列的前20项之和。

程序分析:请抓住分子与分母的变化规律。

程序源代码:

方法一:

实例

#!/usr/bin/python
# -*- coding: UTF-8 -*-

a = 2.0
b = 1.0
s = 0
for n in range(1,21):
s += a / b
t = a
a = a + b
b = t
print (s)

方法二:

实例

#!/usr/bin/python
# -*- coding: UTF-8 -*-

a = 2.0
b = 1.0
s = 0.0
for n in range(1,21):
s += a / b
b,a = a , a + b
print (s)

s = 0.0
for n in range(1,21):
s += a / b
b,a = a , a + b
print (s)

方法三:

实例(Python 2.x)

#!/usr/bin/python
# -*- coding: UTF-8 -*-

a = 2.0
b = 1.0
l = []
l.append(a / b)
for n in range(1,20):
b,a = a,a + b
l.append(a / b)
print reduce(lambda x,y: x + y,l)

实例(Python 3.x)

#!/usr/bin/python

from functools import reduce

a = 2.0
b = 1.0
l = []
l.append(a / b)
for n in range(1,20):
b,a = a,a + b
l.append(a / b)
print (reduce(lambda x,y: x + y,l))

以上实例输出结果为:

32.6602607986

Python 练习实例24 Python 100例