（二）Python3 网页正文提取的各种方法和技巧

本文仅介绍一些简单易用的网页正文提取方法，不涉及正文提取的各种原理。

newspaper

功能非常丰富的一个包，不仅仅支持正文提取，也支持翻译（无字符限制），关键词获取，正确率较高，还有NLP相关的语料库。并且有Python2和Python3两个版本。 安装方式：

pip3 install newspaper3k

使用示例，以今年国庆阅兵的新闻为例：

from newspaper import Article url='http://www.chinanews.com/gn/2019/10-01/8970262.shtml' a=Article(url) a.download() a.parse() print(a.text)

更多功能介绍和示例请见github：https://github.com/codelucas/newspaper

URL2IO

搜索正文提取比较容易找到的一个免费API，通过注册账号获取token，然后使用该API，还有很多功能待开发。优点是简单易用。 官网：http://url2io.applinzi.com/ Github:https://github.com/url2io/url2io-python-sdk 使用方法： 1.注册账号获取token 2.下载url2io.py文件，放到项目文件夹中(或者加进环境变量)。懒得找下载的也可以直接拖到最下面创建个文件复制粘贴一下代码。 3.使用如下代码(token为注册账号获得的一个字符串)获得上例的正文：

import url2io api = url2io.API("7vE7n2DHQ5SUmsZ85ZzOoA") ret = api.article(url='http://www.chinanews.com/gn/2019/10-01/8970262.shtml',fields=['text',]) print(ret['text'])

其他解析器

仅举一个用起来觉得效果不错的，需要安装jparser，lxml。 具体安装的问题我也出现过，但是忘了。遇到问题的也可以问我。 废话不说，代码如下：

import requests,time from jparser import PageModel from urllib.parse import urlparse headers = { 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8', 'Accept-Encoding': 'gzip, deflate', 'Accept-Language': 'zh-CN,zh;q=0.9', 'Connection': 'keep-alive', 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36', } def get_jparser(url): response = requests.get(url, headers=headers) en_code = response.encoding de_code = response.apparent_encoding # print(en_code,de_code,'-----------------') if de_code == None: if en_code in ['utf-8', 'UTF-8']: # en_code=utf-8时，de_code=utf-8,可以获取到内容 de_code = 'utf-8' elif de_code in ['ISO-8859-1', 'ISO-8859-2', 'Windows-1254', 'UTF-8-SIG']: de_code = 'utf-8' html = response.text.encode(en_code, errors='ignore').decode(de_code, errors='ignore') pm = PageModel(html) result = pm.extract() #print("pm.extract result:\n",result) ans = [x['data'] for x in result['content'] if x['type'] == 'text'] #print(ans) for i in range(len(ans)): ans[i]=ans[i]+'\n' content=''.join(ans) return content print(get_jparser("http://www.chinanews.com/gn/2019/10-01/8970262.shtml"))

调用get_jparser函数即可，运行结果为: 但是本方法也有明显的缺点：获取后的部分不能很好的体现网页的结构，由于PageModel内部使用正则表达式，不能很好的针对大部分网站。所以我在以前函数的基础上给列表的每个元素加上换行，以此来分段。

url2io.py代码：

# coding: utf-8 # # This program is free software. It comes without any warranty, to # the extent permitted by applicable law. You can redistribute it # and/or modify it under the terms of the Do What The Fuck You Want # To Public License, Version 2, as published by Sam Hocevar. See # http://sam.zoy.org/wtfpl/COPYING (copied as below) for more details. # # DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE # Version 2, December 2004 # # Copyright (C) 2004 Sam Hocevar <sam@hocevar.net> # # Everyone is permitted to copy and distribute verbatim or modified # copies of this license document, and changing it is allowed as long # as the name is changed. # # DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE # TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION # # 0. You just DO WHAT THE FUCK YOU WANT TO. """a simple url2io sdk example: api = API(token) api.article(url='http://www.url2io.com/products', fields=['next', 'text']) """ __all__ = ['APIError', 'API'] DEBUG_LEVEL = 1 import sys import socket import json import urllib from urllib import request import time from collections import Iterable import importlib importlib.reload(sys) headers = { 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', 'Cache-Control': 'max-age=0', 'Connection': 'keep-alive', 'User-Agent': 'Mozilla/5.txt.0 (X11; Ubuntu; Linux x86_64; rv:22.0) Gecko/20100101 Firefox/22.0' } # 定义头文件，伪装成浏览器 class APIError(Exception): code = None """HTTP status code""" url = None """request URL""" body = None """server response body; or detailed error information""" def __init__(self, code, url, body): self.code = code self.url = url self.body = body def __str__(self): return 'code={s.code}\nurl={s.url}\n{s.body}'.format(s=self) __repr__ = __str__ class API(object): token = None server = 'http://api.url2io.com/' decode_result = True timeout = None max_retries = None retry_delay = None def __init__(self, token, srv=None, decode_result=True, timeout=30, max_retries=5, retry_delay=3): """:param srv: The API server address :param decode_result: whether to json_decode the result :param timeout: HTTP request timeout in seconds :param max_retries: maximal number of retries after catching URL error or socket error :param retry_delay: time to sleep before retrying""" self.token = token if srv: self.server = srv self.decode_result = decode_result assert timeout >= 0 or timeout is None assert max_retries >= 0 self.timeout = timeout self.max_retries = max_retries self.retry_delay = retry_delay _setup_apiobj(self, self, []) def update_request(self, request): """overwrite this function to update the request before sending it to server""" pass def _setup_apiobj(self, apiobj, path): if self is not apiobj: self._api = apiobj self._urlbase = apiobj.server + '/'.join(path) lvl = len(path) done = set() for i in _APIS: if len(i) <= lvl: continue cur = i[lvl] if i[:lvl] == path and cur not in done: done.add(cur) setattr(self, cur, _APIProxy(apiobj, i[:lvl + 1])) class _APIProxy(object): _api = None _urlbase = None def __init__(self, apiobj, path): _setup_apiobj(self, apiobj, path) def __call__(self, post=False, *args, **kwargs): # /article # url = 'http://xxxx.xxx', # fields = ['next',], # if len(args): raise TypeError('only keyword arguments are allowed') if type(post) is not bool: raise TypeError('post argument can only be True or False') url = self.geturl(**kwargs) request = urllib.request.Request(url, headers=headers) self._api.update_request(request) retry = self._api.max_retries while True: retry -= 1 try: ret = urllib.request.urlopen(request, timeout=self._api.timeout).read() break except urllib.error.HTTPError as e: raise APIError(e.code, url, e.read()) except (socket.error, urllib.error.URLError) as e: if retry < 0: raise e _print_debug('caught error: {}; retrying'.format(e)) time.sleep(self._api.retry_delay) if self._api.decode_result: try: ret = json.loads(ret) except: raise APIError(-1, url, 'json decode error, value={0!r}'.format(ret)) return ret def _mkarg(self, kargs): """change the argument list (encode value, add api key/secret) :return: the new argument list""" def enc(x): # if isinstance(x, unicode): # return x.encode('utf-8') # return str(x) return x.encode('utf-8') if isinstance(x, str) else str(x) kargs = kargs.copy() kargs['token'] = self._api.token for (k, v) in kargs.items(): if isinstance(v, Iterable) and not isinstance(v, str): kargs[k] = ','.join([str(i) for i in v]) else: kargs[k] = enc(v) return kargs def geturl(self, **kargs): """return the request url""" return self._urlbase + '?' + urllib.parse.urlencode(self._mkarg(kargs)) def _print_debug(msg): if DEBUG_LEVEL: sys.stderr.write(str(msg) + '\n') _APIS = [ '/article', # '/images', ] _APIS = [i.split('/')[1:] for i in _APIS]