Python中线程和函数的区别--实例演示

来源：互联网发布：厄米特矩阵的性质编辑：程序博客网时间：2024/05/16 18:35

假设我们要检查本地网络中哪些IP地址是可达的哪些是不可达的，我们可以用循环来实现，也可以用线程来实现。

不用线程的实现方式：

#!/usr/bin/pythonimport os, re, threading, commands, timestatus = ["no respones","alive, but 50% package loss","alive","shouldn't occur"]received_packages = re.compile(r"(\d) received")for suffix in range(20,29):    ip = "10.170.9."+str(suffix)    ping_out = os.popen("ping -c 2 " + ip ,"r")    while True:        line = ping_out.read()        if not line:            break        n_received = re.findall(received_packages, line)        if n_received:            print "Status from ", ip, " is ", status[int( n_received[0])],time.ctime(time.time())

执行结果：

Status from 10.170.9.20 is alive Fri Apr 17 13:57:03 2015
Status from 10.170.9.21 is no respones Fri Apr 17 13:57:06 2015
Status from 10.170.9.22 is no respones Fri Apr 17 13:57:09 2015
Status from 10.170.9.23 is no respones Fri Apr 17 13:57:12 2015
Status from 10.170.9.24 is no respones Fri Apr 17 13:57:15 2015
Status from 10.170.9.25 is alive Fri Apr 17 13:57:16 2015
Status from 10.170.9.26 is alive Fri Apr 17 13:57:17 2015
Status from 10.170.9.27 is alive Fri Apr 17 13:57:18 2015
Status from 10.170.9.28 is no respones Fri Apr 17 13:57:22 2015

用线程的实现方式：

#!/usr/bin/pythonimport os, re, threading, commands, timeclass ip_check(threading.Thread):    def __init__(self, ip):        threading.Thread.__init__(self)        self.ip = ip        self.__successful_pings = -1    def run(self):        ping_out = os.popen("ping -c 2 " + self.ip ,"r")        while True:            line = ping_out.read()            if not line:                break            n_received = re.findall(received_packages, line)            if n_received:                self.__successful_pings = int( n_received[0])    def status(self):        if self.__successful_pings == 0:            return "no respones"        elif self.__successful_pings == 1:            return "alive, but 50% package loss"        elif self.__successful_pings == 2:            return "alive"        else:            return "shouldn't occur"received_packages = re.compile(r"(\d) received")check_results = []for suffix in range(20,29):    ip = "10.170.9."+str(suffix)    current = ip_check(ip)    check_results.append(current)    current.start()for el in check_results:    el.join()    print "Status from ", el.ip, " is ", el.status(),time.ctime(time.time())

执行结果：

Status from 10.170.9.20 is alive Fri Apr 17 13:57:39 2015
Status from 10.170.9.21 is no respones Fri Apr 17 13:57:41 2015
Status from 10.170.9.22 is no respones Fri Apr 17 13:57:41 2015
Status from 10.170.9.23 is no respones Fri Apr 17 13:57:41 2015
Status from 10.170.9.24 is no respones Fri Apr 17 13:57:41 2015
Status from 10.170.9.25 is alive Fri Apr 17 13:57:41 2015
Status from 10.170.9.26 is alive Fri Apr 17 13:57:41 2015
Status from 10.170.9.27 is alive Fri Apr 17 13:57:41 2015
Status from 10.170.9.28 is no respones Fri Apr 17 13:57:41 2015

无线程和有线程的结果分析：

有线程的耗时是： 2秒

无线程的耗时是：19秒

线程的方式明显比无线程的快将近10倍。如果在要处理的数据量更大的情况下，线程的处理方式的优势更明显。

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