python 网络爬虫（一）

一、识别网站所用技术

构建网站所使用的技术类型也会对我们如何爬取产生影响。有一个十分有用的工具可以检查网站构建的技术类型---builtwith模块。该模块的安装如下

pip install builtwith

该模块将url作为参数，下载该 url 并其进行分析，返回该网站的技术。

>>> import builtwith
>>> builtwith.parse('http://123.127.249.126:8081/manage/login')
{'programming-languages': ['Java'], 

'web-servers': ['Nginx'], 

'web-frameworks': ['Twitter Bootstrap'], 

'javascript-frameworks': ['jQuery']}

从上面返回的结果可以看出，使用的框架是java 的 Twitter Bootstrap（前段框架利器）

二、寻找网站所有者

对于一些网站，我们可能会关心其所有者是谁。比如、我们已知网站的所有者会封禁网络爬虫，那么我们最好把下载速度控制的更加保守一些，为了找到网站所有者，我们可以使用WHOIS 协议查询域名的注册者是谁。Python 中有一个针对该协议的封装库，器文档地址为 https://pypi.python.org/pypi/python-whois,我们可以通过pip进行安装：

pip install python-whois

下面使用该模块对 http://www.baidu.com 进行WHOIS 查询是返回的结果。

>>>import whois
>>> print(whois.whois('http://www.baidu.com'))
{
  "domain_name": [
    "BAIDU.COM",
    "baidu.com"
  ],
  "registrar": "MarkMonitor, Inc.",
  "whois_server": "whois.markmonitor.com",
  "referral_url": null,
  "updated_date": [
    "2019-05-09 04:30:46",
    "2019-05-08 20:59:33"
  ],
  "creation_date": [
    "1999-10-11 11:05:17",
    "1999-10-11 04:05:17"
  ],
  "expiration_date": [
    "2026-10-11 11:05:17",
    "2026-10-11 00:00:00"
  ],
  "name_servers": [
    "NS1.BAIDU.COM",
    "NS2.BAIDU.COM",
    "NS3.BAIDU.COM",
    "NS4.BAIDU.COM",
    "NS7.BAIDU.COM",
    "ns7.baidu.com",
    "ns2.baidu.com",
    "ns1.baidu.com",
    "ns3.baidu.com",
    "ns4.baidu.com"
  ],
  "status": [
    "clientDeleteProhibited https://icann.org/epp#clientDeleteProhibited",
    "clientTransferProhibited https://icann.org/epp#clientTransferProhibited",
    "clientUpdateProhibited https://icann.org/epp#clientUpdateProhibited",
    "serverDeleteProhibited https://icann.org/epp#serverDeleteProhibited",
    "serverTransferProhibited https://icann.org/epp#serverTransferProhibited",
    "serverUpdateProhibited https://icann.org/epp#serverUpdateProhibited",
    "clientUpdateProhibited (https://www.icann.org/epp#clientUpdateProhibited)",
    "clientTransferProhibited (https://www.icann.org/epp#clientTransferProhibited)",
    "clientDeleteProhibited (https://www.icann.org/epp#clientDeleteProhibited)",
    "serverUpdateProhibited (https://www.icann.org/epp#serverUpdateProhibited)",
    "serverTransferProhibited (https://www.icann.org/epp#serverTransferProhibited)",
    "serverDeleteProhibited (https://www.icann.org/epp#serverDeleteProhibited)"
  ],
  "emails": [
    "abusecomplaints@markmonitor.com",
    "whoisrequest@markmonitor.com"
  ],
  "dnssec": "unsigned",
  "name": null,
  "org": "Beijing Baidu Netcom Science Technology Co., Ltd.",
  "address": null,
  "city": null,
  "state": "Beijing",
  "zipcode": null,
  "country": "CN"
}

可以看出该域名是 属于百度的，实际上却是如此。