基于xpath选择器、PyQuery、正则表达式的格式清理工具详解

时间:2021-05-18

1,使用xpath清理不必要的标签元素,以及无内容标签

from lxml import etree def xpath_clean(self, text: str, xpath_dict: dict) -> str: ''' xpath 清除不必要的元素 :param text: html_content :param xpath_dict: 清除目标xpath :return: string type html_content ''' remove_by_xpath = xpath_dict if xpath_dict else dict() # 必然清除的项目 除非极端情况 一般这些都是要清除的 remove_by_xpath.update({ '_remove_2': '//iframe', '_remove_4': '//button', '_remove_5': '//form', '_remove_6': '//input', '_remove_7': '//select', '_remove_8': '//option', '_remove_9': '//textarea', '_remove_10': '//figure', '_remove_11': '//figcaption', '_remove_12': '//frame', '_remove_13': '//video', '_remove_14': '//script', '_remove_15': '//style' }) parser = etree.HTMLParser(remove_blank_text=True, remove_comments=True) selector = etree.HTML(text, parser=parser) # 常规删除操作,不需要的标签删除 for xpath in remove_by_xpath.values(): for bad in selector.xpath(xpath): bad_string = etree.tostring(bad, encoding='utf-8', pretty_print=True).decode() logger.debug(f"clean article content : {bad_string}") bad.getparent().remove(bad) skip_tip = "name()='img' or name()='tr' or " \ "name()='th' or name()='tbody' or " \ "name()='thead' or name()='table'" # 判断所有p标签,是否有内容存在,没有的直接删除 for p in selector.xpath(f"//*[not({skip_tip})]"): # 跳过逻辑 if p.xpath(f".//*[{skip_tip}]") or \ bool(re.sub('\s', '', p.xpath('string(.)'))): continue bad_p = etree.tostring(p, encoding='utf-8', pretty_print=True).decode() logger.debug(f"clean p tag : {bad_p}") p.getparent().remove(p) return etree.tostring(selector, encoding='utf-8', pretty_print=True).decode()

2,使用pyquery清理标签属性,并返回处理后源码和纯净文本

#!/usr/bin/env python# -*-coding:utf-8-*- from pyquery import PyQuery as pq def pyquery_clean(self, text, url, pq_dict) -> object: ''' pyquery 做出必要的处理, :param text: :param url: :param pq_dict: :return: ''' # 删除pq表达式字典 remove_by_pq = pq_dict if pq_dict else dict() # 标签属性白名单 attr_white_list = ['rowspan', 'colspan'] # 图片链接key img_key_list = ['src', 'data-echo', 'data-src', 'data-original'] # 生成pyquery对象 dom = pq(text) # 删除无用标签 for bad_tag in remove_by_pq.values(): for bad in dom(bad_tag): bad_string = pq(bad).html() logger.debug(f"clean article content : {bad_string}") dom.remove(bad_tag) # 标签各个属性处理 for tag in dom('*'): for key, value in tag.attrib.items(): # 跳过逻辑,保留表格的rowspan和colspan属性 if key in attr_white_list: continue # 处理图片链接,不完整url,补充完整后替换 if key in img_key_list: img_url = self.absolute_url(url, value) pq(tag).remove_attr(key) pq(tag).attr('src', img_url) pq(tag).attr('alt', '') # img标签的alt属性保留为空 elif key == 'alt': pq(tag).attr(key, '') # 其余所有属性做删除操作 else: pq(tag).remove_attr(key) return dom.text(), dom.html()

3,正则表达清理空格以及换行符内容

#!/usr/bin/env python# -*-coding:utf-8-*- import re def regular_clean(self, str1: str, str2: str): ''' 正则表达式处理数据格式 :param str1: content :param str2: html_content :return: 返回处理后的结果 ''' def new_line(text): text = re.sub('<br\s?/?>', '<br>', text) text = re.sub( '</?a>|</?em>|</?html>|</?body>|' '</?head>|<[a-zA-Z]{1,10}\s?/>|' '</?strong>|</?blockquote>|</?b>|' '</?span>|</?i>|</?hr>|</?font>', '', text) text = re.sub('\n', '', text) text = re.sub('<h[1-6]>', '<p>', text) text = re.sub('</h[1-6]>', '</p>', text) text = text.replace('</p>', '</p>\n').replace('<br>', '<br/>') return text str1, str2 = self.clean_blank(str1), self.clean_blank(str2) # TODO 处理空白行问题 # TODO html_content处理 1,删除多余的无法使用的标签以及影响数据展示的标签 2,换行符问题处理以及更换 str2 = new_line(text=str2) return str1, str2

结尾部分,各个方法封装类代码展示

#!/usr/bin/env python# -*-coding:utf-8-*-'''author: szhandate:2020-08-17summery: 清理html_conent以及获取纯净数据格式''' import refrom lxml import etreefrom pyquery import PyQuery as pqfrom urllib.parse import urlsplit, urljoin from loguru import logger class CleanArticle: def __init__( self, text: str, url: str = '', xpath_dict: dict = None, pq_dict: dict = None ): self.text = text self.url = url self.xpath_dict = xpath_dict or dict() self.pq_dict = pq_dict or dict() @staticmethod def absolute_url(baseurl: str, url: str) -> str: ''' 补充url :param baseurl:scheme url :param url: target url :return: complete url ''' target_url = url if urlsplit(url).scheme else urljoin(baseurl, url) return target_url @staticmethod def clean_blank(text): ''' 空白处理 :param text: :return: ''' text = text.replace('&#13;', '').replace('\u3000', '').replace('\t', '').replace('\xa0', '') text = re.sub('\s{2,}', '', text) text = re.sub('\n{2,}', '\n', text) text = text.strip('\n').strip() return text def run(self): ''' :return:处理后的content, html_content ''' if (not bool(self.text)) or (not isinstance(self.text, str)): raise ValueError('html_content has a bad type value') # 首先,使用xpath去除空格,以及注释,iframe, button, form, script, style, video等标签 text = self.xpath_clean(self.text, self.xpath_dict) # 第二步,使用pyquery处理具体细节方面 str1, str2 = self.pyquery_clean(text, self.url, self.pq_dict) # 最终的正则处理 content, html_content = self.regular_clean(str1, str2) return content, html_content def xpath_clean(self, text: str, xpath_dict: dict) -> str: ''' xpath 清除不必要的元素 :param text: html_content :param xpath_dict: 清除目标xpath :return: string type html_content ''' remove_by_xpath = xpath_dict if xpath_dict else dict() # 必然清除的项目 除非极端情况 一般这些都是要清除的 remove_by_xpath.update({ '_remove_2': '//iframe', '_remove_4': '//button', '_remove_5': '//form', '_remove_6': '//input', '_remove_7': '//select', '_remove_8': '//option', '_remove_9': '//textarea', '_remove_10': '//figure', '_remove_11': '//figcaption', '_remove_12': '//frame', '_remove_13': '//video', '_remove_14': '//script', '_remove_15': '//style' }) parser = etree.HTMLParser(remove_blank_text=True, remove_comments=True) selector = etree.HTML(text, parser=parser) # 常规删除操作,不需要的标签删除 for xpath in remove_by_xpath.values(): for bad in selector.xpath(xpath): bad_string = etree.tostring(bad, encoding='utf-8', pretty_print=True).decode() logger.debug(f"clean article content : {bad_string}") bad.getparent().remove(bad) skip_tip = "name()='img' or name()='tr' or " \ "name()='th' or name()='tbody' or " \ "name()='thead' or name()='table'" # 判断所有p标签,是否有内容存在,没有的直接删除 for p in selector.xpath(f"//*[not({skip_tip})]"): # 跳过逻辑 if p.xpath(f".//*[{skip_tip}]") or \ bool(re.sub('\s', '', p.xpath('string(.)'))): continue bad_p = etree.tostring(p, encoding='utf-8', pretty_print=True).decode() logger.debug(f"clean p tag : {bad_p}") p.getparent().remove(p) return etree.tostring(selector, encoding='utf-8', pretty_print=True).decode() def pyquery_clean(self, text, url, pq_dict) -> object: ''' pyquery 做出必要的处理, :param text: :param url: :param pq_dict: :return: ''' # 删除pq表达式字典 remove_by_pq = pq_dict if pq_dict else dict() # 标签属性白名单 attr_white_list = ['rowspan', 'colspan'] # 图片链接key img_key_list = ['src', 'data-echo', 'data-src', 'data-original'] # 生成pyquery对象 dom = pq(text) # 删除无用标签 for bad_tag in remove_by_pq.values(): for bad in dom(bad_tag): bad_string = pq(bad).html() logger.debug(f"clean article content : {bad_string}") dom.remove(bad_tag) # 标签各个属性处理 for tag in dom('*'): for key, value in tag.attrib.items(): # 跳过逻辑,保留表格的rowspan和colspan属性 if key in attr_white_list: continue # 处理图片链接,不完整url,补充完整后替换 if key in img_key_list: img_url = self.absolute_url(url, value) pq(tag).remove_attr(key) pq(tag).attr('src', img_url) pq(tag).attr('alt', '') # img标签的alt属性保留为空 elif key == 'alt': pq(tag).attr(key, '') # 其余所有属性做删除操作 else: pq(tag).remove_attr(key) return dom.text(), dom.html() def regular_clean(self, str1: str, str2: str): ''' 正则表达式处理数据格式 :param str1: content :param str2: html_content :return: 返回处理后的结果 ''' def new_line(text): text = re.sub('<br\s?/?>', '<br>', text) text = re.sub( '</?a>|</?em>|</?html>|</?body>|' '</?head>|<[a-zA-Z]{1,10}\s?/>|' '</?strong>|</?blockquote>|</?b>|' '</?span>|</?i>|</?hr>|</?font>', '', text) text = re.sub('\n', '', text) text = re.sub('<h[1-6]>', '<p>', text) text = re.sub('</h[1-6]>', '</p>', text) text = text.replace('</p>', '</p>\n').replace('<br>', '<br/>') return text str1, str2 = self.clean_blank(str1), self.clean_blank(str2) # TODO 处理空白行问题 # TODO html_content处理 1,删除多余的无法使用的标签以及影响数据展示的标签 2,换行符问题处理以及更换 str2 = new_line(text=str2) return str1, str2 if __name__ == '__main__': with open('html_content.html', 'r', encoding='utf-8') as f: lines = f.readlines() html = '' for line in lines: html += line ca = CleanArticle(text=html) _, html_content = ca.run() print(html_content)

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