python多进程使用及线程池的使用方法代码详解

import os,timeimport sysfrom multiprocessing import Processclass MyProcess(Process):  """docstring for MyProcess"""  def __init__(self, arg, callback):    super(MyProcess, self).__init__()    self.arg = arg    self.callback = callback  def run(self):    self.callback(self.arg)def test(arg):  print("子进程{}开始>>> pid={}".format(arg,os.getpid()))  for i in range(1,5):    sys.stdout.write("子进程{}运行中{}/r".format(arg,i))    sys.stdout.flush()    time.sleep(1)def main():  print("主进程开始>>> pid={}".format(os.getpid()))  myp=MyProcess(1,test)  myp.start()  myp2=MyProcess(2,test)  myp2.start()  myp.join()  myp2.join()  print("主进程终止")if __name__ == '__main__':  main()

from concurrent.futures import ThreadPoolExecutorimport timedef sayhello(a):  print("hello: "+a)  time.sleep(2)def main():  seed=["a","b","c"]  start1=time.time()  for each in seed:    sayhello(each)  end1=time.time()  print("time1: "+str(end1-start1))  start2=time.time()  with ThreadPoolExecutor(3) as executor:    for each in seed:      executor.submit(sayhello,each)  end2=time.time()  print("time2: "+str(end2-start2))  start3=time.time()  with ThreadPoolExecutor(2) as executor1:    executor1.map(sayhello,seed)  end3=time.time()  print("time3: "+str(end3-start3))if __name__ == '__main__':  main()