如何在python多处理中使进程休眠而不使其他进程休眠

Question

How do I make one thread sleep without making other threads sleep in Python, when using the module multiprocessing ? I want to make getDataProcess sleep for some time when the queue has less than 10 elements. During this time the main thread will populate the queue with more data and the while loop will continue executing.

import multiprocessing as mp
import os
import csv
import sys
import subprocess
import time
cur=[]
dataList=[]
def getData(queue):
    global dataList
    print('get data started')
    with open('temp.csv','w+') as file:
        writer=csv.DictWriter(file,fieldnames=['index','name','fileaccess'],lineterminator='\n')
        while not queue.empty():
            cur=queue.get()
            writer.writerow(cur)
            if len(dataList)<=100:
                dataList.append(cur)
                print('appending to datalist',end='\r')
            if len(dataList)==100:
                showData(queue)
            if(queue.qsize()<10):
                print('danger race condition'+str(queue.qsize()))
                if os.path.exists('temp.csv'):
                    try:
                        os.rename('temp.csv','temp.csv')
                        print('may have completed reading')
                    except OSError as e:
                        #time.sleep(10)
                        print('sleeping to prevent end ')

def showData(queue):
    print('showdata started')
    global dataList

    #time.sleep(1)

    print(dataList)
    if(queue.qsize()<100):
        print('danger race condition')
if __name__=="__main__":
    try:
        filename=sys.argv[1]
        key=sys.argv[2]
    except:
        print('arguments not provided')
    queue = mp.Queue() 
    getDataProcess=mp.Process(target=getData,args=(queue,))
    getDataProcessStatus=False
    showDataProcess=mp.Process(target=showData,args=(queue,))
    showDataProcessStatus=False
    with open('archive/data.csv') as file:
        matches=0
        reader=csv.DictReader(file,fieldnames=['index','name','fileaccess'],delimiter=',')
        header=next(reader)
        for i,row in enumerate(reader):
            if(row['fileaccess'][0]=='d'):
                matches+=1
                queue.put(row)
                if(getDataProcessStatus==False):
                        getDataProcess.start()
                        getDataProcessStatus=True
                        print('getdata started')
                # if(matches>200):
                #     if(showDataProcessStatus==False):
                #         print('show data started')
                #         showDataProcess.start()
                #         showDataProcessStatus=True

Answer 1

Use:

time.sleep( delay )

It will make your process sleep without affecting others.