from multiprocessing import Process
def foo(name):
 print('hello,%s'%name)
if __name__ == '__main__':
 p1=Process(target=foo,args=('world',))
 p2 = Process(target=foo, args=('China',))
 p1.start()
 p2.start()
 print('=====主進(jìn)程=====')
 # == == =主進(jìn)程 == == =
 # hello, world
 # hello, China
 #主進(jìn)程和子進(jìn)程并發(fā)執(zhí)行 

from multiprocessing import Process
class MyProcess(Process):
 def __init__(self,name):
  super().__init__()
  self.name = name
 def run(self):
  print('hello,%s'%self.name)
if __name__ == '__main__':
 myprocess1 = MyProcess('world')
 myprocess2 = MyProcess('world')
 myprocess1.start()
 myprocess2.start()

from multiprocessing import Process
import time
class MyProcess(Process):
 def __init__(self,name):
  super().__init__()
  self.name = name
 def run(self):
  time.sleep(3)
  print('hello,%s'%self.name)
if __name__ == '__main__':
 myprocess1=MyProcess('world')
 myprocess1.daemon = True
 myprocess1.start()
 print('結(jié)束')
#不會(huì)輸出‘hello world'，因?yàn)樵O(shè)置為守護(hù)進(jìn)程，主進(jìn)程不會(huì)等待

from multiprocessing import Process
import time
class MyProcess(Process):
 def __init__(self,name):
  super().__init__()
  self.name = name
 def run(self):
  time.sleep(3)
  print('hello,%s'%self.name)
if __name__ == '__main__':
 myprocess1=MyProcess('world')
 myprocess1.daemon = True
 myprocess1.start()
 myprocess1.join() #程序阻塞
 print('結(jié)束')
join()

from multiprocessing import Process,Lock
import time
def a_print(l): #需要傳入對(duì)象，因?yàn)樾畔⒉还蚕?
 l.acquire()
 print('我要打印信息')
 time.sleep(1)
 print('我打印完了')
 l.release()
if __name__ == '__main__':
 l = Lock()
 for i in range(20):
  p = Process(target=a_print,args=(l,))
  p.start()

from multiprocessing import Process,Queue,Semaphore
import time,random
def seat(s,n):
 s.acquire()
 print('學(xué)生%d坐下了'%n)
 time.sleep(random.randint(1,2))
 s.release()
if __name__ == '__main__':
 s = Semaphore(5)
 for i in range(20):
  p = Process(target=seat,args=(s,i))
  p.start()
 print('-----主進(jìn)程-------')

from multiprocessing import Process,Event
import time, random
def eating(event):
 event.wait()
 print('去吃飯的路上...')
def makeing(event):
 print('做飯中')
 time.sleep(random.randint(1,2))
 print('做好了，快來(lái)...')
 event.set()
if __name__ == '__main__':
 event=Event()
 t1 = Process(target=eating,args=(event,))
 t2 = Process(target=makeing,args=(event,))
 t1.start()
 t2.start()
 # 做飯中
 # 做好了，快來(lái)...
 # 去吃飯的路上...

from multiprocessing import Process,Queue
import time
def func1(queue):
 while True:
  info=queue.get()
  if info == None:
   return 
  print(info)
def func2(queue):
 for i in range(10):
  time.sleep(1)
  queue.put('is %d'%i)
 queue.put(None) #結(jié)束的標(biāo)志
if __name__ == '__main__':
 q = Queue()
 p1 = Process(target=func1,args=(q,))
 p2 = Process(target=func2, args=(q,))
 p1.start()
 p2.start()
Queue類的方法，源碼如下：
class Queue(object):
 def __init__(self, maxsize=-1): #可以傳參設(shè)置隊(duì)列最大容量
  self._maxsize = maxsize
 def qsize(self): #返回當(dāng)前時(shí)刻隊(duì)列中的個(gè)數(shù)
  return 0
 def empty(self): #是否為空
  return False
 def full(self): 是否滿了
  return False
 def put(self, obj, block=True, timeout=None): #放值,blocked和timeout。如果blocked為True（默認(rèn)值），并且timeout為正值，該方法會(huì)阻塞timeout指定的時(shí)間，直到該隊(duì)列有剩余的空間。如果超時(shí)，會(huì)拋出Queue.Full異常。如果blocked為False，但該Queue已滿，會(huì)立即拋出Queue.Full異常
  pass
 def put_nowait(self, obj): #=put(False)
  pass
 def get(self, block=True, timeout=None): 獲取值,get方法有兩個(gè)可選參數(shù)：blocked和timeout。如果blocked為True（默認(rèn)值），并且timeout為正值，那么在等待時(shí)間內(nèi)沒有取到任何元素，會(huì)拋出Queue.Empty異常。如果blocked為False，有兩種情況存在，如果Queue有一個(gè)值可用，則立即返回該值，否則，如果隊(duì)列為空，則立即拋出Queue.Empty異常.
  pass
 def get_nowait(self): # = get(False)
  pass
 def close(self): #將隊(duì)列關(guān)閉
  pass
 def join_thread(self): #略，幾乎不用
  pass
 def cancel_join_thread(self):
  pass

from multiprocessing import Pool
import time, random, os
def func(n):
 pid = os.getpid()
 print('進(jìn)程%s正在處理第%d個(gè)任務(wù)'%(pid,n),'時(shí)間%s'%time.strftime('%H-%M-%S'))
 time.sleep(2)
 res = '處理%s'%random.choice(['成功','失敗'])
 return res
if __name__ == '__main__':
 p = Pool(4) #創(chuàng)建4個(gè)進(jìn)程，
 li = []
 for i in range(10):
  res = p.apply(func,args=(i,)) 交給進(jìn)程池處理，處理完成才返回值，會(huì)阻塞，即使池內(nèi)還有空余進(jìn)程，相當(dāng)于順序執(zhí)行
  li.append(res)
 for i in li:
  print(i)

from multiprocessing import Pool
import time, random, os
def func(n):
 pid = os.getpid()
 print('進(jìn)程%s正在處理第%d個(gè)任務(wù)'%(pid,n),'時(shí)間%s'%time.strftime('%H-%M-%S'))
 time.sleep(2)
 res = '處理%s'%random.choice(['成功','失敗'])
 return res

if __name__ == '__main__':
 p = Pool(4)
 li = []
 for i in range(10):
  res = p.apply_async(func,args=(i,)) 結(jié)果不會(huì)立刻返回，遇到阻塞，開啟下一個(gè)進(jìn)程，在這，相當(dāng)于幾乎同時(shí)出現(xiàn)四個(gè)打印結(jié)果（一個(gè)線程處理一個(gè)任務(wù)，處理完下個(gè)任務(wù)才能進(jìn)來(lái)）
  li.append(res)

 p.close() #join之前需要關(guān)閉進(jìn)程池
 p.join() #因?yàn)楫惒?，所以需要等待池?nèi)進(jìn)程工作結(jié)束再繼續(xù)
 for i in li:
  print(i.get()) #i是一個(gè)對(duì)象，通過(guò)get方法獲取返回值，而同步則沒有該方法

from multiprocessing import Pool
import time, random, os
def func(n):
 pid = os.getpid()
 print('進(jìn)程%s正在處理第%d個(gè)任務(wù)'%(pid,n),'時(shí)間%s'%time.strftime('%H-%M-%S'))
 time.sleep(2)
 res = '處理%s'%random.choice(['成功','失敗'])
 return res

def foo(info):
 print(info) #傳入值為進(jìn)程執(zhí)行結(jié)果

if __name__ == '__main__':
 p = Pool(4)
 li = []
 for i in range(10):
  res = p.apply_async(func,args=(i,)，callback = foo) callback()回調(diào)函數(shù)會(huì)在進(jìn)程執(zhí)行完之后調(diào)用（主進(jìn)程調(diào)用） 
  li.append(res)

 p.close() 
 p.join() 
 for i in li:
  print(i.get())