python线程池

一、安装

安装命令
pip install threadpool

# -*- coding: utf-8 -*-

# 使用线程池之前
import time
def sayhello(str):
    print "Hello ",str
    time.sleep(2)

name_list =['xiaozi','aa','bb','cc']
start_time = time.time()
for i in range(len(name_list)):
    sayhello(name_list[i])
print '使用线程池前   %d second'% (time.time()-start_time)

# threadpool的使用

import time
import threadpool
def sayhello(str):
    print "Hello ",str
    time.sleep(2)

name_list =['xiaozi','aa','bb','cc']
start_time = time.time()
pool = threadpool.ThreadPool(10) # 括号中的参数为线程池的尺寸/线程数量
requests = threadpool.makeRequests(sayhello, name_list) # 第一个参数为函数体名称，第二个参数为前面函数调用时需要传入的参数列表
[pool.putRequest(req) for req in requests]
pool.wait()
print '使用线程池后   %d second'% (time.time()-start_time)

运行结果：

Hello  xiaozi
Hello  aa
Hello  bb
Hello  cc
使用线程池前   8 second
Hello  xiaozi
Hello  aa
Hello  bb
Hello  cc
使用线程池后   2 second

可以看出，使用线程池后，运行速度有明显提高。makeRequests（函数体，参数列表）

二、了解线程池threadpool

一、安装与简介

pip install threadpool

pool = ThreadPool(poolsize)  
requests = makeRequests(some_callable, list_of_args, callback)  
[pool.putRequest(req) for req in requests]  
pool.wait()  

第一行定义了一个线程池，表示最多可以创建poolsize这么多线程；

第二行是调用makeRequests创建了要开启多线程的函数，以及函数相关参数和回调函数，其中回调函数可以不写，default是无，也就是说makeRequests只需要2个参数就可以运行；

第三行用法比较奇怪，是将所有要运行多线程的请求扔进线程池，[pool.putRequest(req) for req in requests]等同于

for req in requests:

pool.putRequest(req)

第四行是等待所有的线程完成工作后退出。

二、代码实例

import time
def sayhello(str):
    print "Hello ",str
    time.sleep(2)

name_list =['xiaozi','aa','bb','cc']
start_time = time.time()
for i in range(len(name_list)):
    sayhello(name_list[i])
print '%d second'% (time.time()-start_time)

结果

image.png

改用线程池代码,花费时间更少，更效率

import time
import threadpool  
def sayhello(str):
    print "Hello ",str
    time.sleep(2)

name_list =['xiaozi','aa','bb','cc']
start_time = time.time()
pool = threadpool.ThreadPool(10) 
requests = threadpool.makeRequests(sayhello, name_list) 
[pool.putRequest(req) for req in requests] 
pool.wait() 
print '%d second'% (time.time()-start_time)

结果

image.png

当函数有多个参数的情况，函数调用时第一个解包list，第二个解包dict，所以可以这样：

def hello(m, n, o):
    """"""
    print "m = %s, n = %s, o = %s"%(m, n, o)
     
 
if __name__ == '__main__':
     
   # 方法1  
    lst_vars_1 = ['1', '2', '3']
    lst_vars_2 = ['4', '5', '6']
    func_var = [(lst_vars_1, None), (lst_vars_2, None)]
    # 方法2
    dict_vars_1 = {'m':'1', 'n':'2', 'o':'3'}
    dict_vars_2 = {'m':'4', 'n':'5', 'o':'6'}
    func_var = [(None, dict_vars_1), (None, dict_vars_2)]    
     
    pool = threadpool.ThreadPool(2)
    requests = threadpool.makeRequests(hello, func_var)
    [pool.putRequest(req) for req in requests]
    pool.wait()        

需要把所传入的参数进行转换，然后带入线程池。

def getuserdic():
    username_list=['xiaozi','administrator']
    password_list=['root','','abc123!','123456','password','root']
    userlist = []
    
    for username in username_list:
        
        user =username.rstrip()
        for password in password_list:
            pwd = password.rstrip()
            userdic ={}
            userdic['user']=user
            userdic['pwd'] = pwd
            tmp=(None,userdic)
            userlist.append(tmp)
    return userlist