7.寻找素数

定义：除了1 和本身之外，不被任何数整除。 7 = 7*1   是     9 = 3*3 不是

代码：

 1 #!/usr/bin/env python
 2 # encoding: utf-8
 3 """
 4 @author: 侠之大者kamil
 5 @file: 8.素数.py
 6 @time: 2016/4/9 18:25
 7 """
 8 import math
 9 def isPrimeNumber(n,s):
10     #for k in range(2,int(math.sqrt(n)) + 1):
11     for k in s:#s为小于n的素数的集合
12         if k * k > n:break#保证k 小于n的平方根，for k in range(2,int(math.sqrt(n)) + 1)
13         if n % k ==0 : return None #
14     return n
15 prime=[]
16 for n in range(2,300):
17     res = isPrimeNumber(n,prime)
18     if res:
19         prime.append(res)
20 print(prime)

结果：

ssh://[email protected]:22/usr/bin/python3 -u /home/kamil/py22/趣味百题/8.素数.py
[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293]

Process finished with exit code 0