def pi(N):
'计算pi的值'
# 创建一个奇数序列:1,3,5,7,9...
js = itertools.count(1, 2)
# 取奇数序列的前N项
num = itertools.takewhile(lambda x: x < 2 * N, js)
sum = 0
# 添加正负号并用4除: 4/1, -4/3, 4/5, -4/7, 4/9, ...
for i in num:
if i % 4 == 1:
i = 4 / i
else:
i = -4 / i
sum += i
#print('i:', i, 'sum:', sum)
return sum
Velskerd