浅谈python3.x pool.map()方法的实质

"""
探索pool.map多进程执行方式的实质
"""

from multiprocessing import Pool
from time import sleep
from datetime import datetime

class forMap:
  def __init__(self):
    self.name = '没啥用的初始化'

  def forPrinit(self, i):
    sleep(i)
    print(i)
    return i ** 2

if __name__ == '__main__':
  s = datetime.now()
  tt = forMap()
  # 进程池中创建两个进程，调用计算机的两个内核去帮我做事。
  p = Pool(2)

  l = [2, 4, 6]
  rList = p.map(tt.forTest, l)
  print(rList)

  p.close()
  p.join()

  e = datetime.now()
  print('多进程执行时间：', e - s)

if __name__ == '__main__':
  s = datetime.now()
  tt = forMap()
  # 进程池中创建三个进程
  p = Pool(3)

  l = [2, 4, 6]
  rList = p.map(tt.forTest, l)
  print(rList)

  p.close()
  p.join()

  e = datetime.now()
  print('多进程执行时间：', e - s)

if __name__ == '__main__':
  s = datetime.now()
  tt = forMap()
  # 进程池中创建三个进程
  p = Pool(3)

  l = [2, 4, 6, 8]
  rList = p.map(tt.forTest, l)
  print(rList)

  p.close()
  p.join()

  e = datetime.now()
  print('多进程执行时间：', e - s)

if __name__ == '__main__':
  s = datetime.now()
  tt = forMap()
  # 进程池中创建三个进程
  p = Pool(2)

  l = [2, 4, 8, 6]
  rList = p.map(tt.forTest, l)
  print(rList)

  p.close()
  p.join()

  e = datetime.now()
  print('多进程执行时间：', e - s)