圆月山庄资源网 Design By www.vgjia.com

使用 ProcessPoolExecutor

from concurrent.futures import ProcessPoolExecutor, as_completed
import random

斐波那契数列

当 n 大于 30 时抛出异常

def fib(n):
  if n > 30:
    raise Exception('can not > 30, now %s' % n)
  if n <= 2:
    return 1
  return fib(n-1) + fib(n-2)

准备数组

nums = [random.randint(0, 33) for _ in range(0, 10)]
'''
[13, 17, 0, 22, 19, 33, 7, 12, 8, 16]
'''

方案一:submit

submit 输出结果按照子进程执行结束的先后顺序,不可控

 with ProcessPoolExecutor(max_workers=3) as executor:
    futures = {executor.submit(fib, n):n for n in nums}
    for f in as_completed(futures):
      try:
        print('fib(%s) result is %s.' % (futures[f], f.result()))
      except Exception as e:
        print(e)
'''
fib(13) result is 233.
fib(17) result is 1597.
fib(0) result is 1.
fib(22) result is 17711.
fib(19) result is 4181.
can not > 30, now 33
fib(7) result is 13.
fib(12) result is 144.
fib(8) result is 21.
fib(16) result is 987.

'''

等价写法:

 with ProcessPoolExecutor(max_workers=3) as executor:
    futures = {}
    for n in nums:
      job = executor.submit(fib, n)
      futures[job] = n

    for job in as_completed(futures):
      try:
        re = job.result()
        n = futures[job]
        print('fib(%s) result is %s.' % (n, re))
      except Exception as e:
        print(e)
'''
fib(13) result is 233.
fib(17) result is 1597.
fib(0) result is 1.
fib(22) result is 17711.
can not > 30, now 33
fib(7) result is 13.
fib(19) result is 4181.
fib(8) result is 21.
fib(12) result is 144.
fib(16) result is 987.
'''

方案二:map

map 输出结果按照输入数组的顺序

缺点:某一子进程异常会导致整体中断

 with ProcessPoolExecutor(max_workers=3) as executor:
    try:
      results = executor.map(fib, nums)
      for num, result in zip(nums, results):
        print('fib(%s) result is %s.' % (num, result))
    except Exception as e:
      print(e)
'''
fib(13) result is 233.
fib(17) result is 1597.
fib(0) result is 1.
fib(22) result is 17711.
fib(19) result is 4181.
can not > 30, now 33
'''

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。

标签:
python,ProcessPoolExecutor,python,多进程并行

圆月山庄资源网 Design By www.vgjia.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站文章均来自网站采集或用户投稿,网站不提供任何软件下载或自行开发的软件! 如有用户或公司发现本站内容信息存在侵权行为,请邮件告知! 858582#qq.com
圆月山庄资源网 Design By www.vgjia.com

稳了!魔兽国服回归的3条重磅消息!官宣时间再确认!

昨天有一位朋友在大神群里分享,自己亚服账号被封号之后居然弹出了国服的封号信息对话框。

这里面让他访问的是一个国服的战网网址,com.cn和后面的zh都非常明白地表明这就是国服战网。

而他在复制这个网址并且进行登录之后,确实是网易的网址,也就是我们熟悉的停服之后国服发布的暴雪游戏产品运营到期开放退款的说明。这是一件比较奇怪的事情,因为以前都没有出现这样的情况,现在突然提示跳转到国服战网的网址,是不是说明了简体中文客户端已经开始进行更新了呢?