Python多进程编程multiprocessing代码实例

import multiprocessing
import time


def get_html(n):
  time.sleep(n)
  print('sub process %s' % n)
  return n


if __name__ == '__main__':
  # 多进程编程
  process = multiprocessing.Process(target=get_html, args=(2,))
  process.start()
  print(process.pid) # 进程号
  process.join()
  print('main process success!')

  # 使用多进程池编程
  pool = multiprocessing.Pool(multiprocessing.cpu_count())
  # result =pool.apply_async(get_html, (3,))
  # # 关闭pool
  # pool.close()
  # # 等待所有任务完成
  # pool.join()
  # print(result.get())

  # 使用imap方法, 有序执行,且直接返回结果值
  # for result in pool.imap(get_html, [1, 5, 3]):
  #   print('{} sleep success'.format(result))
  # pool.close()

  # imap_unordered 与imap相似,但是谁先执行完成,谁先返回结果
  # for result in pool.imap_unordered(get_html, [1, 5, 3]):
  #   print('{} sleep success'.format(result))
  # pool.close()