python定时执行指定函数的方法

本文实例讲述了python定时执行指定函数的方法。分享给大家供大家参考。具体实现方法如下：

    # time a function using time.time() and the a @ function decorator
    # tested with Python24  vegaseat  21aug2005
    import time
    def print_timing(func):
      def wrapper(*arg):
        t1 = time.time()
        res = func(*arg)
        t2 = time.time()
        print '%s took %0.3f ms' % (func.func_name, (t2-t1)*1000.0)
        return res
      return wrapper
    # declare the @ decorator just before the function, invokes print_timing()
    @print_timing
    def getPrimeList(n):
      """ returns a list of prime numbers from 2 to < n using a sieve algorithm"""
      if n < 2: return []
      if n == 2: return [2]
      # do only odd numbers starting at 3
      s = range(3, n+1, 2)
      # n**0.5 may be slightly faster than math.sqrt(n)
      mroot = n ** 0.5
      half = len(s)
      i = 0
      m = 3
      while m <= mroot:
        if s[i]:
          j = (m*m-3)//2
          s[j] = 0
          while j < half:
            s[j] = 0
            j += m
        i = i+1
        m = 2*i+3
      return [2]+[x for x in s if x]
    if __name__ == "__main__":
      print "prime numbers from 2 to <10,000,000 using a sieve algorithm"
      primeList = getPrimeList(10000000)
      time.sleep(2.5)
    """
    my output -->
    prime numbers from 2 to <10,000,000 using a sieve algorithm
    getPrimeList took 4750.000 ms
    """

希望本文所述对大家的Python程序设计有所帮助。