another method

Author: wangxx

AK-wang/A0000/sushu_v0.1.py

@@ -0,0 +1,30 @@
+#!/bin/env python
+#-*-coding:utf-8-*-
+
+import sys
+import math 
+
+def prime(n):
+    if n%2 == 0:
+        return n==2
+    if n%3 == 0:
+        return n==3
+    if n%5 == 0:
+        return n==5
+    for p in xrange(7,int(math.sqrt(n))+1,2):    #只考虑奇数作为可能因子
+        if n%p == 0:
+            return 0
+    return 1  
+
+if __name__ == "__main__":
+    n = int(sys.argv[1])
+    for i in xrange(2,n+1): #1不是素数,从2开始
+        if prime(i):
+            print i
+
+#$ time ./sushu_v0.1.py 100000|wc -l
+#9592
+
+#real	0m0.287s
+#user	0m0.282s
+#sys	0m0.009s