Updated scoring algorithm to match readability.js v1.7.1
This commit is contained in:
Yuri Baburov
parent
96f476181c
commit
f55f16baa1
@ -2,7 +2,7 @@
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import re
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from lxml.html.clean import Cleaner
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bad_attrs = ['width', 'height', 'style', '[-a-z]*color', 'background[-a-z]*']
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bad_attrs = ['width', 'height', 'style', '[-a-z]*color', 'background[-a-z]*', 'on*']
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single_quoted = "'[^']+'"
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double_quoted = '"[^"]+"'
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non_space = '[^ "\'>]+'
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@ -1,8 +1,9 @@
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#!/usr/bin/env python
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from collections import defaultdict
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from cleaners import html_cleaner, clean_attributes
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from collections import defaultdict
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from htmls import build_doc, get_body, get_title, shorten_title
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from lxml.etree import tostring, tounicode
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from lxml.html import fragment_fromstring, document_fromstring
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import logging
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import re
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import sys
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@ -10,10 +11,10 @@ import sys
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logging.basicConfig(level=logging.INFO)
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REGEXES = {
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'unlikelyCandidatesRe': re.compile('share|bookmark|adwrapper|ad_wrapper|combx|comment|disqus|foot|header|menu|meta|nav|rss|shoutbox|sidebar|sponsor',re.I),
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'okMaybeItsACandidateRe': re.compile('and|article|body|column|main',re.I),
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'positiveRe': re.compile('caption|article|body|content|entry|hentry|page|pagination|post|text',re.I),
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'negativeRe': re.compile('adwrapper|ad_wrapper|share|bookmark|nav|combx|comment|contact|foot|footer|footnote|link|media|meta|promo|related|scroll|shoutbox|sponsor|tags|widget',re.I),
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'unlikelyCandidatesRe': re.compile('combx|comment|community|disqus|extra|foot|header|menu|remark|rss|shoutbox|sidebar|sponsor|ad-break|agegate|pagination|pager|popup|tweet|twitter',re.I),
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'okMaybeItsACandidateRe': re.compile('and|article|body|column|main|shadow',re.I),
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'positiveRe': re.compile('article|body|content|entry|hentry|main|page|pagination|post|text|blog|story',re.I),
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'negativeRe': re.compile('combx|comment|com-|contact|foot|footer|footnote|masthead|media|meta|outbrain|promo|related|scroll|shoutbox|sidebar|sponsor|shopping|tags|tool|widget',re.I),
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'divToPElementsRe': re.compile('<(a|blockquote|dl|div|img|ol|p|pre|table|ul)',re.I),
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#'replaceBrsRe': re.compile('(<br[^>]*>[ \n\r\t]*){2,}',re.I),
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#'replaceFontsRe': re.compile('<(\/?)font[^>]*>',re.I),
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@ -21,21 +22,21 @@ REGEXES = {
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#'normalizeRe': re.compile('\s{2,}/'),
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#'killBreaksRe': re.compile('(<br\s*\/?>(\s| ?)*){1,}/'),
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#'videoRe': re.compile('http:\/\/(www\.)?(youtube|vimeo)\.com', re.I),
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#skipFootnoteLink: /^\s*(\[?[a-z0-9]{1,2}\]?|^|edit|citation needed)\s*$/i,
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}
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def describe(node):
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def describe(node, depth=1):
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if not hasattr(node, 'tag'):
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return "[text]"
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return "%s#%s.%s" % (
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node.tag, node.get('id', ''), node.get('class',''))
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def log_candidates(candidates, print_format=""):
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for candidate, value in candidates.items():
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logging.info( "%s\t%s\t%s\t%s" %(id(candidate), describe(candidate), value['content_score'], describe(value['elem'])))
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#def _text(node):
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# return " ".join(node.findall(text=True))
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return "[%s]" % type(node)
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name = node.tag
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if node.get('id', ''): name += '#'+node.get('id')
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if node.get('class', ''):
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name += '.' + node.get('class').replace(' ','.')
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if name[:4] in ['div#', 'div.']:
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name = name[3:]
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if depth and node.getparent() is not None:
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return name+' - '+describe(node.getparent(), depth-1)
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return name
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def to_int(x):
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if not x: return None
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@ -46,6 +47,14 @@ def to_int(x):
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return int(x[:-2]) * 12
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return int(x)
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def clean(text):
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text = re.sub('\s*\n\s*', '\n', text)
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text = re.sub('[ \t]{2,}', ' ', text)
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return text.strip()
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def text_length(i):
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return len(clean(i.text_content() or ""))
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class Unparseable(ValueError):
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pass
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@ -92,12 +101,12 @@ class Document:
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for i in self.tags(self.html, 'script', 'style'):
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i.drop_tree()
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for i in self.tags(self.html, 'body'):
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i.set('id', 'readabilityBody')
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if ruthless:
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self.remove_unlikely_candidates()
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self.transform_misused_divs_into_paragraphs()
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candidates = self.score_paragraphs(self.options.get('min_text_length', self.TEXT_LENGTH_THRESHOLD))
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#log_candidates(candidates)
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candidates = self.score_paragraphs()
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best_candidate = self.select_best_candidate(candidates)
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if best_candidate:
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@ -130,11 +139,12 @@ class Document:
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# Things like preambles, content split by ads that we removed, etc.
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sibling_score_threshold = max([10, best_candidate['content_score'] * 0.2])
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output = self._parse("<div/>")
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for sibling in best_candidate['elem'].getparent().getchildren():
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output = document_fromstring('<div/>')
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best_elem = best_candidate['elem']
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for sibling in best_elem.getparent().getchildren():
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#if isinstance(sibling, NavigableString): continue#in lxml there no concept of simple text
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append = False
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if sibling is best_candidate['elem']:
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if sibling is best_elem:
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append = True
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sibling_key = sibling #HashableElement(sibling)
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if sibling_key in candidates and candidates[sibling_key]['content_score'] >= sibling_score_threshold:
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@ -152,65 +162,78 @@ class Document:
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if append:
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output.append(sibling)
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if output is not None: output.append(best_candidate['elem'])
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#if output is not None:
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# output.append(best_elem)
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return output
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def select_best_candidate(self, candidates):
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sorted_candidates = sorted(candidates.values(), key=lambda x: x['content_score'], reverse=True)
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self.debug("Top 5 candidates:")
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for candidate in sorted_candidates[:5]:
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elem = candidate['elem']
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self.debug("Candidate %s with score %s" % (describe(elem), candidate['content_score']))
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self.debug("Top 5 : %6.3f %s" % (candidate['content_score'], describe(elem)))
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if len(sorted_candidates) == 0:
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return None
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best_candidate = sorted_candidates[0]
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#self.debug("Best candidate %s with score %s" % (describe(best_candidate['elem']), best_candidate['content_score']))
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return best_candidate
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def get_link_density(self, elem):
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link_length = len("".join([i.text or "" for i in elem.findall(".//a")]))
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text_length = len(elem.text_content())
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return float(link_length) / max(text_length, 1)
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link_length = 0
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for i in elem.findall(".//a"):
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link_length += text_length(i)
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#if len(elem.findall(".//div") or elem.findall(".//p")):
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# link_length = link_length
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total_length = text_length(elem)
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return float(link_length) / max(total_length, 1)
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def score_paragraphs(self, min_text_length):
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def score_paragraphs(self, ):
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MIN_LEN = self.options.get('min_text_length', self.TEXT_LENGTH_THRESHOLD)
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candidates = {}
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self.debug(str([describe(node) for node in self.tags(self.html, "div")]))
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elems = self.tags(self.html, "div", "p", "td", 'li', "a")
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#self.debug(str([describe(node) for node in self.tags(self.html, "div")]))
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for elem in elems:
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ordered = []
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for elem in self.tags(self.html, "p", "pre", "td"):
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parent_node = elem.getparent()
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if parent_node is None:
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continue
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grand_parent_node = parent_node.getparent()
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elem_key = elem#HashableElement(elem)
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parent_key = parent_node#HashableElement(parent_node)
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grand_parent_key = grand_parent_node#HashableElement(grand_parent_node)
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inner_text = elem.text_content()
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inner_text = clean(elem.text_content() or "")
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inner_text_len = len(inner_text)
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# If this paragraph is less than 25 characters, don't even count it.
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if (not inner_text) or len(inner_text) < min_text_length:
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if inner_text_len < MIN_LEN:
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continue
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if parent_key not in candidates:
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candidates[parent_key] = self.score_node(parent_node)
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if grand_parent_node is not None and grand_parent_key not in candidates:
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candidates[grand_parent_key] = self.score_node(grand_parent_node)
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if parent_node not in candidates:
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candidates[parent_node] = self.score_node(parent_node)
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ordered.append(parent_node)
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if grand_parent_node is not None and grand_parent_node not in candidates:
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candidates[grand_parent_node] = self.score_node(grand_parent_node)
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ordered.append(grand_parent_node)
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content_score = 1
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content_score += len(inner_text.split(','))
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content_score += min([(len(inner_text) / 100), 3])
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if elem not in candidates:
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candidates[elem_key] = self.score_node(elem)
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candidates[elem_key]['content_score'] += content_score
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candidates[parent_key]['content_score'] += content_score
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content_score += min((inner_text_len / 100), 3)
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#if elem not in candidates:
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# candidates[elem] = self.score_node(elem)
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#WTF? candidates[elem]['content_score'] += content_score
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candidates[parent_node]['content_score'] += content_score
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if grand_parent_node is not None:
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candidates[grand_parent_key]['content_score'] += content_score / 2.0
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candidates[grand_parent_node]['content_score'] += content_score / 2.0
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# Scale the final candidates score based on link density. Good content should have a
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# relatively small link density (5% or less) and be mostly unaffected by this operation.
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for elem, candidate in candidates.items():
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candidate['content_score'] *= (1 - self.get_link_density(elem))
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#self.debug("candidate %s scored %s" % (describe(elem), candidate['content_score']))
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for elem in ordered:
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candidate = candidates[elem]
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ld = self.get_link_density(elem)
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score = candidate['content_score']
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self.debug("Candid: %6.3f %s link density %.3f -> %6.3f" % (score, describe(elem), ld, score*(1-ld)))
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candidate['content_score'] *= (1 - ld)
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return candidates
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@ -237,43 +260,68 @@ class Document:
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name = elem.tag.lower()
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if name == "div":
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content_score += 5
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elif name == "blockquote":
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elif name in ["pre", "td", "blockquote"]:
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content_score += 3
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elif name == "form":
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elif name in ["address", "ol", "ul", "dl", "dd", "dt", "li", "form"]:
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content_score -= 3
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elif name == "th":
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elif name in ["h1", "h2", "h3", "h4", "h5", "h6", "th"]:
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content_score -= 5
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return { 'content_score': content_score, 'elem': elem }
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return {
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'content_score': content_score,
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'elem': elem
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}
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def debug(self, *a):
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#if self.options['debug']:
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logging.debug(*a)
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def remove_unlikely_candidates(self):
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for elem in self.html.iter():
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s = "%s%s" % (elem.get('class', ''), elem.get('id', ''))
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self.debug(s)
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s = "%s %s" % (elem.get('class', ''), elem.get('id', ''))
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#self.debug(s)
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if REGEXES['unlikelyCandidatesRe'].search(s) and (not REGEXES['okMaybeItsACandidateRe'].search(s)) and elem.tag != 'body':
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self.debug("Removing unlikely candidate - %s" % (s,))
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self.debug("Removing unlikely candidate - %s" % describe(elem))
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elem.drop_tree()
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def transform_misused_divs_into_paragraphs(self):
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for elem in self.html.iter():
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if not isinstance(elem.tag, basestring):
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raise Exception("You have to strip html comments!")
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if elem.tag.lower() == "div":
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for elem in self.tags(self.html, 'div'):
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# transform <div>s that do not contain other block elements into <p>s
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if not REGEXES['divToPElementsRe'].search(unicode(''.join(map(tostring, list(elem))))):
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self.debug("Altering div(#%s.%s) to p" % (elem.get('id', ''), elem.get('class', '')))
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#self.debug("Altering %s to p" % (describe(elem)))
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elem.tag = "p"
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#print "Fixed element "+describe(elem)
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for elem in self.tags(self.html, 'div'):
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if elem.text and elem.text.strip():
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p = fragment_fromstring('<p/>')
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p.text = elem.text
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elem.text = None
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elem.insert(0, p)
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#print "Appended "+tounicode(p)+" to "+describe(elem)
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for pos, child in reversed(list(enumerate(elem))):
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if child.tail and child.tail.strip():
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p = fragment_fromstring('<p/>')
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p.text = child.tail
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child.tail = None
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elem.insert(pos + 1, p)
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#print "Inserted "+tounicode(p)+" to "+describe(elem)
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if child.tag == 'br':
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#print 'Dropped <br> at '+describe(elem)
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child.drop_tree()
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def tags(self, node, *tag_names):
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for tag_name in tag_names:
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for e in node.findall('.//%s' %tag_name):
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for e in node.findall('.//%s' % tag_name):
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yield e
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def reverse_tags(self, node, *tag_names):
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for tag_name in tag_names:
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for e in reversed(node.findall('.//%s' % tag_name)):
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yield e
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def sanitize(self, node, candidates):
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MIN_LEN = self.options.get('min_text_length', self.TEXT_LENGTH_THRESHOLD)
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for header in self.tags(node, "h1", "h2", "h3", "h4", "h5", "h6"):
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if self.class_weight(header) < 0 or self.get_link_density(header) > 0.33:
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header.drop_tree()
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@ -282,47 +330,48 @@ class Document:
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elem.drop_tree()
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allowed = {}
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# Conditionally clean <table>s, <ul>s, and <div>s
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for el in self.tags(node, "table", "ul", "div"):
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for el in self.reverse_tags(node, "table", "ul", "div"):
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if el in allowed:
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continue
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weight = self.class_weight(el)
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el_key = el #HashableElement(el)
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if el_key in candidates:
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content_score = candidates[el_key]['content_score']
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if el in candidates:
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content_score = candidates[el]['content_score']
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#print '!',el, '-> %6.3f' % content_score
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else:
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content_score = 0
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tag = el.tag
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if weight + content_score < 0:
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self.debug("Cleaned %s with score %6.3f and weight %-3s" %
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(describe(el), content_score, weight, ))
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el.drop_tree()
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self.debug("Conditionally cleaned %s with weight %s and content score %s because score + content score was less than zero." %
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(describe(el), weight, content_score))
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elif len(el.text_content().split(",")) < 10:
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elif el.text_content().count(",") < 10:
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counts = {}
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for kind in ['p', 'img', 'li', 'a', 'embed', 'input']:
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counts[kind] = len(el.findall('.//%s' %kind))
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counts["li"] -= 100
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content_length = len(el.text_content()) # Count the text length excluding any surrounding whitespace
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content_length = text_length(el) # Count the text length excluding any surrounding whitespace
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link_density = self.get_link_density(el)
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parent_node = el.getparent()
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if parent_node:
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if parent_node is not None:
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if parent_node in candidates:
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content_score = candidates[parent_node]['content_score']
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else:
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content_score = 0
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pweight = self.class_weight(parent_node) + content_score
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pname = parent_node.tag
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else:
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pweight = 0
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pname = "no parent"
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#if parent_node is not None:
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#pweight = self.class_weight(parent_node) + content_score
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#pname = describe(parent_node)
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#else:
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#pweight = 0
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#pname = "no parent"
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to_remove = False
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reason = ""
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#if el.tag == 'div' and counts["img"] >= 1:
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# continue
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if counts["p"] and counts["img"] > counts["p"]:
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reason = "too many images"
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reason = "too many images (%s)" % counts["img"]
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to_remove = True
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elif counts["li"] > counts["p"] and tag != "ul" and tag != "ol":
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reason = "more <li>s than <p>s"
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@ -330,68 +379,69 @@ class Document:
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elif counts["input"] > (counts["p"] / 3):
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reason = "less than 3x <p>s than <input>s"
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to_remove = True
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elif content_length < (self.options.get('min_text_length', self.TEXT_LENGTH_THRESHOLD)) and (counts["img"] == 0 or counts["img"] > 2):
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reason = "too short a content length without a single image"
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elif content_length < (MIN_LEN) and (counts["img"] == 0 or counts["img"] > 2):
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reason = "too short content length %s without a single image" % content_length
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to_remove = True
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elif weight < 25 and link_density > 0.2:
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reason = "too many links for its weight less than 25 (#{weight})"
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reason = "too many links %.3f for its weight %s" % (link_density, weight)
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to_remove = True
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elif weight >= 25 and link_density > 0.5:
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reason = "too many links for its weight (#{weight})"
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reason = "too many links %.3f for its weight %s" % (link_density, weight)
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to_remove = True
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elif (counts["embed"] == 1 and content_length < 75) or counts["embed"] > 1:
|
||||
reason = "<embed>s with too short a content length, or too many <embed>s"
|
||||
reason = "<embed>s with too short content length, or too many <embed>s"
|
||||
to_remove = True
|
||||
if el.tag == 'div' and counts['img'] >= 1 and to_remove:
|
||||
imgs = el.findall('.//img')
|
||||
valid_img = False
|
||||
self.debug(tounicode(el))
|
||||
for img in imgs:
|
||||
# if el.tag == 'div' and counts['img'] >= 1 and to_remove:
|
||||
# imgs = el.findall('.//img')
|
||||
# valid_img = False
|
||||
# self.debug(tounicode(el))
|
||||
# for img in imgs:
|
||||
#
|
||||
# height = img.get('height')
|
||||
# text_length = img.get('text_length')
|
||||
# self.debug ("height %s text_length %s" %(repr(height), repr(text_length)))
|
||||
# if to_int(height) >= 100 or to_int(text_length) >= 100:
|
||||
# valid_img = True
|
||||
# self.debug("valid image" + tounicode(img))
|
||||
# break
|
||||
# if valid_img:
|
||||
# to_remove = False
|
||||
# self.debug("Allowing %s" %el.text_content())
|
||||
# for desnode in self.tags(el, "table", "ul", "div"):
|
||||
# allowed[desnode] = True
|
||||
|
||||
height = img.get('height')
|
||||
width = img.get('width')
|
||||
self.debug ("height %s width %s" %(repr(height), repr(width)))
|
||||
if to_int(height) >= 100 or to_int(width) >= 100:
|
||||
valid_img = True
|
||||
self.debug("valid image" + tounicode(img))
|
||||
break
|
||||
if valid_img:
|
||||
to_remove = False
|
||||
self.debug("Allowing %s" %el.text_content())
|
||||
for desnode in self.tags(el, "table", "ul", "div"):
|
||||
allowed[desnode] = True
|
||||
#find x non empty preceeding and succeeding siblings
|
||||
"""
|
||||
#find x non empty preceding and succeeding siblings
|
||||
i, j = 0, 0
|
||||
x = 1
|
||||
siblings = []
|
||||
for sib in el.itersiblings():
|
||||
self.debug(sib.text_content())
|
||||
sib_content_length = len(sib.text_content())
|
||||
#self.debug(sib.text_content())
|
||||
sib_content_length = text_length(sib)
|
||||
if sib_content_length:
|
||||
i =+ 1
|
||||
siblings.append(sib_content_length)
|
||||
if i == x:
|
||||
break
|
||||
for sib in el.itersiblings(preceding=True):
|
||||
self.debug(sib.text_content())
|
||||
sib_content_length = len(sib.text_content())
|
||||
#self.debug(sib.text_content())
|
||||
sib_content_length = text_length(sib)
|
||||
if sib_content_length:
|
||||
j =+ 1
|
||||
siblings.append(sib_content_length)
|
||||
if j == x:
|
||||
break
|
||||
self.debug(str(siblings))
|
||||
#self.debug(str(siblings))
|
||||
if siblings and sum(siblings) > 1000 :
|
||||
to_remove = False
|
||||
self.debug("Allowing %s" %el.text_content())
|
||||
self.debug("Allowing %s" % describe(el))
|
||||
for desnode in self.tags(el, "table", "ul", "div"):
|
||||
allowed[desnode] = True
|
||||
"""
|
||||
|
||||
if to_remove:
|
||||
self.debug("Conditionally cleaned %s#%s.%s with weight %s and content score %s because it has %s." %
|
||||
(el.tag, el.get('id',''), el.get('class', ''), weight, content_score, reason))
|
||||
self.debug("pname %s pweight %s" %(pname, pweight))
|
||||
self.debug("Cleaned %6.3f %s with weight %s cause it has %s." %
|
||||
(content_score, describe(el), weight, reason))
|
||||
#print tounicode(el)
|
||||
#self.debug("pname %s pweight %.3f" %(pname, pweight))
|
||||
el.drop_tree()
|
||||
|
||||
for el in ([node] + [n for n in node.iter()]):
|
||||
|
||||
Loading…
Reference in New Issue
Block a user