Process

• 队列 . manager 传递数据
• 两个进程池

进程

• 进程资源不共享，manage（）方法可以通信
• 进程消耗CPU资源

进程间资源不共享--- 进程间的通信

import os
from multiprocessing import Queue,Process

def write_data(data_queue):
    for i in range(30):
        data_queue.put(i)
    print(os.getpid())

def read_data(data_queue):
    while not data_queue.empty():
        print(data_queue.get())
    print(os.getpid())

if __name__ == '__main__':
    q = Queue()
     # group: Any   分组
     # target: Optional[Callable]进程要处理的任务
     # name: Optional[str]  进程名
     # args: Iterable[Any]  参数
     # kwargs: Mapping[Any, Any] = ...,参数包
     # daemon: Optional[bool] = ...) -> None: ...    

    process1 = Process(target=write_data,name='p1',args=(q,))
    process1.start()
    process1.join()

    process2 = Process(target=read_data,name='p2',args=(q,))
    process2.start()
    process2.join()

实现共享进程间资源共享--- 进程间的通信

import os,time
from multiprocessing import Pool,Manager

def write_data(data_queue,num):
    for inf in range(num):
        data_queue.put(inf)
    print('write_over',os.getpid())

def read_data(data_queue):
    while not data_queue.empty():
        a = data_queue.get()
        print(a)
    print('read_over')

if __name__ == '__main__':
    q = Manager().Queue()
    #创建进程池
    pool = Pool(4)
    pool.apply_async(write_data,(q,40))

    time.sleep(2)
    start = time.time()
    pool.apply_async(read_data,(q,))
    #关闭
    pool.close()
    end = time.time()
    print(end-start)

进程池（1）

from multiprocessing import Pool
from fake_useragent import UserAgent
import requests


def download_image(imageUrl,imageName):
    print(imageUrl,imageName)
    req_header={'User-Agent':UserAgent().random}
    response = requests.get(url=imageUrl,headers=req_header)
    if response.status_code==200:
        return response.status_code,imageName,response.content

def download_done(future):
    print('执行了回调方法')
    print(future)
    imageName = future[1]
    with open(imageName,'wb') as file:
        file.write(future[2])

if __name__ == '__main__':
    pool = Pool(4)
    for i in range(40):
        imageurl = 'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=2811473792,2413507956&fm=11&gp=0.jpg'
        pool.apply_async(func=download_image,args=(imageurl,'img{}.jpg'.format(i)),callback=download_done)
    pool.close()
    pool.join()

进程池（2）python自带的

from concurrent.futures import ProcessPoolExecutor
from fake_useragent import UserAgent
import requests

def download_image(imgUrl,imgName):
    print(imgUrl,imgName)
    req_header = {'UserAgent':UserAgent().random}
    response = requests.get(url=imgUrl,headers=req_header)
    if response.status_code==200:
        return response.status_code,imgName,response.content
def download_done(future):
    print('执行了回调函数')
    print(future.result())

if __name__ == '__main__':
    #创建进程池  #python自带的____容易出现问题
    pool = ProcessPoolExecutor(4)
    for i in range(40,70):
        imgurl= 'https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=2811473792,2413507956&fm=11&gp=0.jpg'
        #往进程池添加任务 fn(函数名称)
        handler = pool.submit(download_image,imgurl,'img{}.jpg'.format(i) )
        #添加回调方法
        handler.add_done_callback(download_done)
    #shutdown里默认有join方法
    pool.shutdown()
    print('over_process')