解决使用Python检查本地网络中运行的Web服务器的问题

如果我们要检查本地网络中运行的 Web 服务器，可以使用 Python 的 socket 模块来进行网络连接测试。以下是一个简单的示例代码，演示如何检查本地网络中运行的 Web 服务器：

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1、问题背景

在学习如何使用 Python 时，一位用户希望编写一段代码来检查本地网络中是否有人运行着 Web 服务器。他们使用提供的代码遇到了一些错误，因此寻求社区的帮助来解决这些问题。

以下错误代码：

#!/usr/bin/env python

import httplib
last = 1
while last <> 255:
        url = "10.1.1." + "last"
        connection = httplib.HTTPConnection("url", 80)
        connection.request("GET","/")
        response = connection.getresponse()
        print (response.status)
        last = last + 1

2、解决方案

方案 1：使用正确的 Python 语法和错误处理

import httplib
import socket


for i in range(1, 256):
    try:
        url = "10.1.1.%d" % i
        connection = httplib.HTTPConnection(url, 80)
        connection.request("GET","/")
        response = connection.getresponse()
        print url + ":", response.status
    except socket.error:
        print url + ":", "error!"

方案 2：使用更 Pythonic 的代码风格和错误处理

import urllib
import threading
import socket

def t_run(thread_list, chunks):
    t_count = len(thread_list)
    print("Running %s jobs in groups of %s threads" % (t_count, chunks))
    for x in range(t_count / chunks + 1):
        i = x * chunks
        i_c = min(i + chunks, t_count)
        c = len([t.start() for t in thread_list[i:i_c]])
        print("Started %s threads for jobs %s...%s" % (c, i, i_c - 1))
        c = len([t.join() for t in thread_list[i:i_c]])
        print("Finished %s threads for job index %s" % (c, i))

def url_scan(ip_base, timeout=5):
    socket.setdefaulttimeout(timeout)
    def f(url):
        # print("-- Trying (%s)" % url)
        try:
            # the print will only complete if there's a server there
            r = urllib.urlopen(url)
            if r:
                print("## (%s) got %s bytes" % (url, len(r.read())))
            else:
                print("## (%s) failed to connect" % url)
        except IOError, msg:
            if str(msg)=="[Errno socket error] timed out":
                return
            if str(msg)=="[Errno socket error] (10061, 'Connection refused')":
                return
            print("## (%s) got error '%s'" % (url, msg))
            return [threading.Thread(target=f, args=("http://" + ip_base + str(x) + ":" + str(p),)) for x in range(255) for p in [80, 8080]]

# run them (increase chunk size depending on your memory)
# also, try different timeouts
t_run(url_scan("209.131.36."), 100)
t_run(url_scan("209.131.36.", 30), 100)

方案 3：修复变量名中的引号

#!/usr/bin/env python

import httplib
last = 1
while last <> 255:
        url = "10.1.1.%d" % last
        connection = httplib.HTTPConnection(url, 80)
        connection.request("GET","/")
        response = connection.getresponse()
        print (response.status)
        last = last + 1

方案 4：移除引号并使用正确的变量名

#!/usr/bin/env python

import httplib
last = 1
while last <> 255:
        url = "10.1.1." + str(last)
        connection = httplib.HTTPConnection(url, 80)
        connection.request("GET","/")
        response = connection.getresponse()
        print (response.status)
        last = last + 1