當我嘗試運行代碼時，它會得到以下錯誤：PicklingError：Can not pickle <type'function'>：attribute lookup __builtin __。function failed

Question

我的代碼有什麼問題？謝謝

import os 
import os.path 
import time 
global item_count 
#-*- coding: cp936 -*- 
import MySQLdb 
import MySQLdb.cursors 
import threading 
import multiprocessing 
from time import sleep,ctime 


def qucun(): 

    #connect to mysql 
    conn=MySQLdb.connect(host="localhost",user="root",passwd="caihong") 
    cursor=conn.cursor() 
    try: 
     cursor.execute("""create database if not exists quad""") 
    except: 
     print 'Quad is exist' 


    conn.select_db('quad') 
    conn=MySQLdb.connect(host="localhost",user="root",passwd="caihong",db="quad") 
    #get cursor 
    cursor=conn.cursor() 

    try: 
     cursor.execute("""create table if not exists record(fn1 varchar(100), 
     fn2 varchar(100),fn3 varchar(100),fn4 varchar(100), 
     fn5 varchar(100),fn6 varchar(100),fn7 varchar(100),fn8 varchar(100))""") 
    except: 
     print 'Table record is exist' 

    loops=['2013071818_1.txt','2013071818_2.txt','2013071818_3.txt','2013071818_4.txt','2013071818_5.txt'] 




    def loop(nloop,filename): 


     print 'This loop%s start at:'%nloop,ctime() 
     #connect to quad 
     conn=MySQLdb.connect(host="localhost",user="root",passwd="caihong",db="quad") 
     conn.select_db('quad') 
     #get cursor 
     cursor=conn.cursor() 

     newitem=open('C:\\Python27\\caihong\\%s'%filename,'r') 
     data=[line.strip() for line in newitem.readlines()] 
     print data 
     ##put data into value 
     values=['%s'%data[0],'%s'%data[1],'%s'%data[2],'%s'%data[3],'%s'%data[4], 
       '%s'%data[5],'%s'%data[6],'%s'%data[7]] 

     cursor.execute("""insert into record values(%s,%s,%s,%s,%s,%s,%s,%s)""",values); 

     conn.commit() 
     cursor.close() 
     sleep(2) 
     print 'This loop done at',ctime() 



    if __name__=='__main__': 

     print 'starting at:',ctime() 
     threads=[] 
     nloops=range(len(loops)) 
     pool=multiprocessing.Pool(processes=2) 
     for i in nloops: 
      t=pool.apply_async(loop,(i,loops[i])) 


     pool.close() 
     pool.join() 

     if t.successful(): 
      print 'successful' 




     print 'all Done at:',ctime() 
     os.system("pause") 

qucun() 

Answer 1

1. 您正試圖調用本地定義的函數異步。
2. 您正試圖在進程之間共享打開的連接。

首先是棘手2.7實施和第二任何多處理

你必須使用過程池中的每個進程單獨的連接是不可能的。

import os 
import os.path 
import time 
global item_count 
#-*- coding: cp936 -*- 
import MySQLdb 
import MySQLdb.cursors 
import threading 
import multiprocessing 
from time import sleep,ctime 

CONNECTION = None 

def close_connection(): 
    CONNECTION.close() 

def get_connection(): 
    global CONNECTION 

    #If this process pool member launched for a first time - create connection 
    if CONNECTION is None: 

     conn = MySQLdb.connect(host="localhost", 
           user="root", 
           passwd="caihong") 
     cursor = conn.cursor() 
     try: 
      cursor.execute("""create database if not exists quad""") 
     except: 
      print 'Quad is exist' 

     conn.select_db('quad') 

     CONNECTION = MySQLdb.connect(host="localhost", 
            user="root", 
            passwd="caihong", 
            db="quad") 

     cursor = CONNECTION.cursor() 

     try: 
      cursor.execute("""create table if not exists record(fn1 varchar(100), 
      fn2 varchar(100),fn3 varchar(100),fn4 varchar(100), 
      fn5 varchar(100),fn6 varchar(100),fn7 varchar(100),fn8 varchar(100))""") 
     except: 
      print 'Table record is exist' 

     # we dont need to close connection after each insert. 
     # insted - register a finalizer once 
     # so it will be called right before Pool.close() 
     multiprocessing.util.Finalize(CONNECTION, close_connection, exitpriority=1) 

    #use existing connection 
    return CONNECTION 

def loop(nloop, filename): 
    conn = get_connection() 
    cursor = conn.cursor() 

    print 'This loop %s start at: %s'%(nloop, ctime()) 
    with open('C:\\Python27\\caihong\\%s'%filename, 'r') as newitem: 
     data = [line.strip() for line in newitem.readlines()] 

     # values=['%s'%data[0],'%s'%data[1],'%s'%data[2],'%s'%data[3],'%s'%data[4], 
     #   '%s'%data[5],'%s'%data[6],'%s'%data[7]] 
     # ^^^ Thats a bad way to stringify list 

     cursor.execute('insert into record values(%s)', ','.join(data)); 

    conn.commit() 

    # we dont need to close connection after each insert. 
    # cursor.close() 
    print 'This loop done at', ctime() 


LOOPS = ['2013071818_1.txt', '2013071818_2.txt', '2013071818_3.txt', '2013071818_4.txt', '2013071818_5.txt'] 

if __name__=='__main__': 
    pool = multiprocessing.Pool(processes=2) 
    results = [] 
    for i, loopfile in enumerate(LOOPS): 
     results.apply(pool.apply_async(loop, (i, loopfile))) 

    pool.close() 
    pool.join() 

    if all((res.successful() for res in results)): 
     print 'successful' 

    print 'all Done at:', ctime() 
     os.system('pause')