python判断素数的方法

 #运用python的数学函数    

 import math    

 def isPrime(n):
     if n <= 1:
     return False
     for i in range(2, int(math.sqrt(n)) + 1):
     if n % i == 0:
         return False
     return True   

 #单行程序扫描素数    

 from math import sqrt
 N = 100
 [ p for p in   range(2, N) if 0 not in [ p% d for d in range(2, int(sqrt(p))+1)] ]    

 #运用python的itertools模块    

 from itertools import count
 def isPrime(n):
     if n <= 1:
         return False
     for i in count(2):
         if i * i > n:
             return True
         if n % i == 0:
             return False   

 #不使用模块的两种方法    

 def isPrime(n):
     if n <= 1:
         return False
     i = 2
     while i*i <= n:
         if n % i == 0:
             return False
         i += 1
     return True   

 def isPrime(n):
     if n <= 1:
         return False
     if n == 2:
         return True
     if n % 2 == 0:
         return False
     i = 3
     while i * i <= n:
         if n % i == 0:
             return False
         i += 2
     return True