利用 Python 实现多任务进程

import multiprocessing  
def process(index):  
    print(f'Process: {index}')  
if __name__ == '__main__':  
    for i in range(5):  
        p = multiprocessing.Process(target=process, args=(i,))  
        p.start()  

from multiprocessing import Process 
import time 
 
class MyProcess(Process): 
    def __init__(self,loop): 
        Process.__init__(self) 
        self.loop = loop 
 
 
    def run(self): 
        for count in range(self.loop): 
            time.sleep(1) 
            print(f'Pid:{self.pid} LoopCount: {count}') 
if __name__ == '__main__': 
    for i in range(2,5): 
        p = MyProcess(i) 
        p.start() 

from multiprocessing import Queue 
import multiprocessing 
 
def download(p): # 下载数据 
    lst = [11,22,33,44] 
    for item in lst: 
        p.put(item) 
    print('数据已经下载成功....') 
 
 
def savedata(p): 
    lst = [] 
    while True: 
        data = p.get() 
        lst.append(data) 
        if p.empty(): 
            break 
    print(lst) 
 
def main(): 
    p1 = Queue() 
 
    t1 = multiprocessing.Process(target=download,args=(p1,)) 
    t2 = multiprocessing.Process(target=savedata,args=(p1,)) 
 
    t1.start() 
    t2.start() 
 
 
if __name__ == '__main__': 
    main() 
数据已经下载成功.... 
[11, 22, 33, 44] 

import multiprocessing 
 
a = 1 
 
 
def demo1(): 
    global a 
    a += 1 
 
 
def demo2(): 
    print(a) 
 
def main(): 
    t1 = multiprocessing.Process(target=demo1) 
    t2 = multiprocessing.Process(target=demo2) 
 
    t1.start() 
    t2.start() 
 
if __name__ == '__main__': 
    main() 

from multiprocessing import Pool 
import os,time,random 
 
def worker(a): 
    t_start = time.time() 
    print('%s开始执行,进程号为%d'%(a,os.getpid())) 
 
    time.sleep(random.random()*2) 
    t_stop = time.time() 
    print(a,"执行完成,耗时%0.2f"%(t_stop-t_start)) 
 
 
if __name__ == '__main__': 
    po = Pool(3)        # 定义一个进程池 
    for i in range(0,10): 
        po.apply_async(worker,(i,))    # 向进程池中添加worker的任务 
 
    print("--start--") 
    po.close()       
 
    po.join()        
    print("--end--") 

import multiprocessing 
import os 
import time 

def copy_file(Q,oldfolderName,newfolderName,file_name): 
    # 文件复制,不需要返回 
    time.sleep(0.5) 
    # print('\r从%s文件夹复制到%s文件夹的%s文件'%(oldfolderName,newfolderName,file_name),end='') 
 
    old_file = open(oldfolderName + '/' + file_name,'rb') # 待复制文件 
    content = old_file.read() 
    old_file.close() 
 
    new_file = open(newfolderName + '/' + file_name,'wb') # 复制出的新文件 
    new_file.write(content) 
    new_file.close() 
 
    Q.put(file_name) # 向Q队列中添加文件 

def main(): 
    oldfolderName = input('请输入要复制的文件夹名字:') # 步骤1获取要复制文件夹的名字(可以手动创建,也可以通过代码创建,这里我们手动创建) 
    newfolderName = oldfolderName + '复件' 
    # 步骤二 创建一个新的文件夹 
    if not os.path.exists(newfolderName): 
        os.mkdir(newfolderName) 
 
    filenames = os.listdir(oldfolderName) # 3.获取文件夹里面所有待复制的文件名 
    # print(filenames) 
 
    pool = multiprocessing.Pool(5) # 4.创建进程池 
 
    Q = multiprocessing.Manager().Queue() # 创建队列,进行通信 
    for file_name in filenames: 
        pool.apply_async(copy_file,args=(Q,oldfolderName,newfolderName,file_name)) # 5.向进程池添加任务 
      po.close() 
 
    copy_file_num = 0 
    file_count = len(filenames) 
    # 不知道什么时候完成,所以定义一个死循环 
    while True: 
        file_name = Q.get() 
        copy_file_num += 1 
        time.sleep(0.2) 
        print('\r拷贝进度%.2f %%'%(copy_file_num  * 100/file_count),end='') # 做一个拷贝进度条 
 
        if copy_file_num >= file_count: 
            break 

if __name__ == '__main__': 
    main()