python中的进程

from multiprocessing import Process,Pool #进程池
import os,time
def run(i):
    time.sleep(1)
    print ("in the process",os.getpid())
    return i+100
def bar(arg):
    print ('bar is ',os.getpid())
if __name__=='__main__':
    p=Pool(5)
    for i in range(10):
        p.apply_async(func=run,args=(i,),callback=bar)#apply是串行执行进程 apply_async是并行执行进程。其中callback是回调方法，调用一个进程结束时执行，用于一些后续工作。如写入数据库日志等。
    p.close()
    p.join()  #必须是先close，然后再join.

 

#多进程 中的队列操作
from  multiprocessing import Process,Queue
import time,os

def run(name,qq):
    # time.sleep(1)
    print(name,'sellp ')
    qq.put('abc')

if __name__=='__main__':
    q=Queue()
    mp1=Process(target=run,args=('Jack',q))
    mp1.start()
    print(q.get())

#多进程中，使用Manager共享数据
from multiprocessing import Process,Manager
import os

def pm(di,li):
    di[os.getpid()]=os.getppid()
    li.append(os.getpid())
if __name__=='__main__':
    o_list=[]
    with Manager() as manage:
        d1=manage.dict()
        l1=manage.list(range(5))
        for i in range(10):
            p=Process(target=pm,args=(d1,l1))
            p.start()
            o_list.append(p)
        for i in o_list:
            i.join()
        print (d1,l1)

#简单的gevent操作。
import gevent
import os,time

def func1():
    print ('in the func1 A')
    gevent.sleep(2)
    print ('in the func1 B')
def func2():
    print('in the func2 A')
    gevent.sleep(3)
    print('in the func2 B')
def func3():
    print('in the func3 A')
    gevent.sleep(1)
    print('in the func3 B')
start_time=time.time()
gevent.joinall([gevent.spawn(func1),
                gevent.spawn(func2),
                gevent.spawn(func3)])
print ("time ",time.time()-start_time)

#用gevent urllib-request实现的协程爬虫。
from urllib import request
from gevent import monkey
import gevent,time

monkey.patch_all()

def hd(url):
    print ("Get:%s"%url)
    resp=request.urlopen(url)
    data=resp.read()
    print("%s data from is %s"%(len(data),url))
urllist=["http://www.python.org","https://www.yahoo.com/","http://www.orace.com/"]

start_time=time.time()
for i in urllist:
    hd(i)
print ("同步时间：",time.time()-start_time)


start_time_y=time.time()
gevent.joinall(
    [gevent.spawn(hd,urllist[0]),
     gevent.spawn(hd,urllist[1]),
     gevent.spawn(hd,urllist[2])
     ])
print("异步时间：",time.time()-start_time_y)

 

转载于:https://www.cnblogs.com/lzszs/p/8984468.html