from multiprocessing import Process
import os
 
# 子进程要执行的代码
def run_proc(name):
print (‘Run child process %s (%s)...‘ % (name, os.getpid()))
 
if __name__==‘__main__‘:
print (‘Parent process %s.‘ % os.getpid())
p = Process(target=run_proc, args=(‘test‘,))
print (‘Process will start.‘)
p.start()
p.join()
print (‘Process end.‘)

from multiprocessing import Pool
import os, time, random
 
def long_time_task(name):
print (‘Run task %s (%s)...‘ % (name, os.getpid())）
start = time.time()
time.sleep(random.random() * 3)
end = time.time()
print (‘Task %s runs %0.2f seconds.‘ % (name, (end - start))）

if __name__==‘__main__‘:
print (‘Parent process %s.‘ % os.getpid()）
p = Pool()
for i in range(5):
p.apply_async(long_time_task, args=(i,))
print ‘Waiting for all subprocesses done...‘
p.close()
p.join()
print (‘All subprocesses done.‘)

if __name__==‘__main__‘:
# 父进程创建Queue，并传给各个子进程：
q = Queue()
pw = Process(target=write, args=(q,))
pr = Process(target=read, args=(q,))
# 启动子进程pw，写入:
pw.start()
# 启动子进程pr，读取:
pr.start()
# 等待pw结束:
pw.join()
# pr进程里是死循环，无法等待其结束，只能强行终止:
pr.terminate()