thzxx
e94cbe0783
A. fetch.py 补齐 Wayback 兜底 (修复重大 gap) - v2.0.1 gap: fetch.py 独立调用 403 时无 Wayback 兜底 (仅 search.py --fetch 有) - AI Agent 用 fetch.py -u URL 直接抓取被墙站点时, 403 后无任何回退 - 修复: fetch.py main() 增加 Wayback 兜底逻辑 + --no-fallback flag - 共享逻辑抽取到 common.py: should_try_wayback() + build_wayback_url() B. --research 研究模式 - 给定主题自动扩展 5 个多角度查询: overview/profile/background/works/review - 确定性规则 (不依赖 AI 判断), 跨进程可复现 - 输出含 research_topic + research_queries 元数据, AI Agent 可按角度结构化汇编 - 与 --query/--queries-file 互斥, 支持所有输出格式 (json/brief/urls/csv) - 三态退出码: 0=有结果, 2=全部空, 1=全部错误 C. 被墙站点智能回退 - common.py 增加 HARD_BLOCKED_DOMAINS: 百度百科/知乎/微博/微信公众号/豆瓣等 - is_hard_blocked_domain() 精确匹配 + 子域匹配 - 命中被墙站点时: 主抓取失败后立即 Wayback (不等 should_try_wayback 判断) - search.py _should_try_fallback 增加 url 参数, 被墙站点直接触发兜底 真实测试验证 (search.metona.cn 实例): - fetch.py 百度百科兜底: 403 → Wayback 恢复 150,493 chars ✓ - --research 模式: 5 角度查询扩展 + research 元数据 + 三态退出码 ✓ - 被墙站点检测: Hard-blocked domain detected 日志 + 自动 Wayback ✓ 测试: 503 个全部通过 (新增 45 个: test_wayback_shared + test_research_mode) 来源: 另一个 AI Agent 反馈 Wikipedia/百度百科/知乎 fetch 失败, 需要多角度搜索+失败回退+被墙站点列表
1000 lines
40 KiB
Python
1000 lines
40 KiB
Python
#!/usr/bin/env python3
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"""Fetch a web page and extract readable content.
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Downloads page content via HTTP GET and extracts clean, readable text.
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Strips navigation, ads, scripts, and other boilerplate using heuristic rules.
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Dependencies: Python 3.8+ stdlib. Install `requests` and `beautifulsoup4`
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for improved extraction quality (optional, falls back to stdlib).
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"""
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import argparse
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import logging
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import random
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import re
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import sys
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import time
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import urllib.error
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import urllib.request
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from collections import namedtuple
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from html.parser import HTMLParser
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from pathlib import Path
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from typing import Optional
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# Allow running standalone from any working directory
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sys.path.insert(0, str(Path(__file__).resolve().parent))
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from _config import USER_AGENT, VERSION
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from common import (
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FALLBACK_UAS,
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RETRYABLE_STATUS,
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RETRY_BACKOFF_BASE,
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apply_proxy,
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build_auth_headers,
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build_browser_headers,
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build_wayback_url,
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compute_backoff_delay,
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detect_charset,
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force_utf8_stdout,
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get_ua_for_domain,
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is_hard_blocked_domain,
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is_retryable_error,
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parse_retry_after,
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resolve_auth_basic,
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resolve_auth_bearer,
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setup_logging,
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should_try_wayback,
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)
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logger = logging.getLogger("searxng.fetch")
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# ----- Auth helpers -----
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# build_auth_headers is imported from common.py
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# ----- stdlib HTML-to-text extractor -----
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class TextExtractor(HTMLParser):
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"""Extract visible text from HTML, skipping non-content elements."""
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SKIP_TAGS = {"script", "style", "nav", "footer", "header",
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"noscript", "iframe", "svg", "canvas", "template"}
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BLOCK_TAGS = {"p", "div", "article", "section", "li", "h1", "h2", "h3",
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"h4", "h5", "h6", "blockquote", "pre", "table", "tr",
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"br", "hr", "main", "aside", "form", "fieldset"}
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def __init__(self):
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super().__init__()
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self._skip_depth = 0
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self._lines = []
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self._current_line = []
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self._block_pending = False
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def handle_starttag(self, tag, attrs):
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tag_lower = tag.lower()
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if tag_lower in self.SKIP_TAGS:
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self._skip_depth += 1
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elif tag_lower in self.BLOCK_TAGS:
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self._flush_line()
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self._block_pending = True
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def handle_endtag(self, tag):
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tag_lower = tag.lower()
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if tag_lower in self.SKIP_TAGS and self._skip_depth > 0:
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self._skip_depth -= 1
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elif tag_lower in self.BLOCK_TAGS:
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self._flush_line()
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def handle_data(self, data):
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if self._skip_depth > 0:
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return
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text = data.strip()
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if text:
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self._current_line.append(text)
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self._block_pending = False
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def _flush_line(self):
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if self._current_line:
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self._lines.append(" ".join(self._current_line))
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self._current_line = []
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if self._block_pending:
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self._lines.append("")
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self._block_pending = False
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def get_text(self) -> str:
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self._flush_line()
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text = "\n".join(self._lines)
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text = re.sub(r"\n{3,}", "\n\n", text)
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return text.strip()
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# ----- Enhanced extraction with BeautifulSoup (optional) -----
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_HAS_BS4 = False
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_HAS_REQUESTS = False
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try:
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import requests as _requests
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_HAS_REQUESTS = True
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except ImportError:
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pass
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try:
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from bs4 import BeautifulSoup as _BeautifulSoup
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_HAS_BS4 = True
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except ImportError:
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pass
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def extract_with_stdlib(html_content: str) -> str:
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"""Extract text using stdlib HTMLParser."""
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extractor = TextExtractor()
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extractor.feed(html_content)
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return extractor.get_text()
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def extract_with_bs4(html_content: str) -> str:
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"""Extract text using BeautifulSoup for better quality.
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v2.0.0 增强：当 article/main/role=main/content 类 div 都找不到时，
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使用 readability-lite 文本密度算法从 body 中选择最可能是正文的
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子元素，避免回退到整个 body 导致噪声（导航/侧边栏/页脚）污染输出。
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"""
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soup = _BeautifulSoup(html_content, "html.parser")
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for tag in soup(["script", "style", "nav", "footer", "header",
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"noscript", "iframe", "svg", "canvas"]):
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tag.decompose()
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main = (soup.find("article") or
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soup.find("main") or
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soup.find(role="main") or
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soup.find("div", class_=re.compile(r"content|article|post|entry")) or
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soup.body)
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if main is None:
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main = soup
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# v2.0.0: 如果 main 是 body（兜底），用 readability-lite 提取正文
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if main.name == "body":
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main = _readability_lite(main) or main
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text = main.get_text(separator="\n", strip=True)
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lines = [line.strip() for line in text.split("\n") if line.strip()]
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text = "\n".join(lines)
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text = re.sub(r"\n{3,}", "\n\n", text)
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return text
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def _readability_lite(root) -> "Optional[object]":
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"""readability-lite：用文本密度算法选择最可能是正文的子元素。
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算法（受 readability.js 启发，简化版）：
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1. 遍历 body 下所有 div/section/article 子节点
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2. 计算每个节点的"文本密度" = 纯文本字符数 / 标签数
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3. 排除明显是导航/侧边栏的节点（class/id 含 nav/sidebar/menu/footer）
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4. 返回文本密度最高且字符数 > 200 的节点
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返回 bs4 Tag 或 None（找不到合适节点时）。
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这是 extract_with_bs4 的兜底增强，不改变原有 article/main 优先级。
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"""
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if root is None:
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return None
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candidates = root.find_all(["div", "section", "article"])
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if not candidates:
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return None
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# 排除明显非正文节点
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noise_pattern = re.compile(r"nav|sidebar|menu|footer|header|comment|"
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r"related|share|social|widget|advert|banner|"
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r"cookie|popup|modal", re.IGNORECASE)
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best_node = None
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best_score = 0.0
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for node in candidates:
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# 排除 class/id 命中噪声模式的节点
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cls = " ".join(node.get("class", []))
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nid = node.get("id", "")
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if noise_pattern.search(cls) or noise_pattern.search(nid):
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continue
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# 计算纯文本字符数（去空白）
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text = node.get_text(separator=" ", strip=True)
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text_len = len(text)
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if text_len < 200:
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continue # 正文至少 200 字符
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# 计算标签数（粗略：所有后代标签）
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tag_count = len(node.find_all())
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if tag_count == 0:
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continue
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# 文本密度 = 字符数 / 标签数；越高越可能是正文
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density = text_len / tag_count
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# 加权：段落 <p> 数量也是正文信号
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p_count = len(node.find_all("p"))
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score = density + (p_count * 10)
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if score > best_score:
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best_score = score
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best_node = node
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return best_node
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def extract_text(html_content: str) -> str:
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"""Extract readable text from HTML, preferring bs4 if available."""
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if _HAS_BS4:
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try:
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return extract_with_bs4(html_content)
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except Exception:
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pass
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return extract_with_stdlib(html_content)
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# ----- Tree-based HTML-to-Markdown converter (robust) -----
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class MarkdownConverter(HTMLParser):
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"""Convert HTML to Markdown using a tag-stack approach.
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Handles nested tags in <a> elements correctly unlike regex. Supports:
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* GFM tables (``<table>`` → ``| a | b |`` with separator row)
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* fenced code blocks (``<pre>`` → triple-backtick fences)
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* inline code (``<code>`` → backticks)
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* blockquotes (``<blockquote>`` → ``> `` prefix per line)
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* headings, lists, images, emphasis, links
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"""
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def __init__(self):
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super().__init__()
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self._output = []
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self._skip_depth = 0
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self._list_stack = [] # list of [type, counter] for ol numbering
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self._pending_indent = "" # preserved leading indent for li/dd
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self._block_buffer = ""
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self._link_href = None
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self._link_text = []
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self._in_link = False
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self._in_pre = False
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self._pre_content = []
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self._heading_level = 0
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self._block_empty = True
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# Blockquote support
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self._in_blockquote = False
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# Table support (GFM)
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self._in_table = False
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self._table_rows = [] # list of (cells_list, is_header)
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self._current_row = None
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self._current_cell = None
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self._in_cell = False
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def _append_inline(self, text: str):
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"""Append inline markup, routing to cell/link/block buffer.
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In cell context, fragments go to ``_current_cell`` so table cell text
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accumulates correctly. In link context, they go to ``_link_text``
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and are collapsed at ``</a>`` time. Otherwise they append to the
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block buffer; whitespace is normalized at ``_flush_block`` time.
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"""
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if self._in_cell:
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self._current_cell.append(text)
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elif self._in_link:
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self._link_text.append(text)
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else:
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self._block_buffer += text
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self._block_empty = False
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def _flush_block(self):
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t = self._block_buffer
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# Normalize whitespace: collapse runs of spaces/tabs/newlines
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t = re.sub(r'\s+', ' ', t).strip()
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if t:
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if self._in_blockquote:
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# Prefix each line with "> " for markdown blockquote syntax
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t = "\n".join(
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("> " + line) if line.strip() else ">"
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for line in t.split("\n")
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)
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if self._pending_indent:
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self._output.append(self._pending_indent + t)
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else:
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self._output.append(t)
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self._block_buffer = ""
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self._block_empty = True
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self._pending_indent = ""
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def _emit_table(self):
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"""Emit a GFM table from accumulated rows.
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The first row becomes the header; a ``| --- | --- |`` separator row
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follows; remaining rows become the body. Cells are padded to the
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header width so the table renders correctly in strict GFM parsers.
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"""
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if not self._table_rows:
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return
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header_row, _ = self._table_rows[0]
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body_rows = self._table_rows[1:]
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if not header_row:
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return
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ncols = len(header_row)
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self._output.append("| " + " | ".join(header_row) + " |")
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self._output.append("| " + " | ".join("---" for _ in range(ncols)) + " |")
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for row, _ in body_rows:
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# Pad short rows; truncate long rows to header width
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while len(row) < ncols:
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row.append("")
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self._output.append("| " + " | ".join(row[:ncols]) + " |")
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self._output.append("")
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def handle_starttag(self, tag, attrs):
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tag_lower = tag.lower()
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attrs_dict = dict(attrs)
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if tag_lower in ("script", "style", "nav", "footer", "header",
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"noscript", "iframe", "svg", "canvas", "template"):
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self._skip_depth += 1
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return
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if self._skip_depth > 0:
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self._skip_depth += 1
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return
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# Table structural elements are handled up-front so cell content
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# routing (via _in_cell) takes effect before any other tag handler.
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if tag_lower == "table":
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self._flush_block()
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self._in_table = True
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self._table_rows = []
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return
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if self._in_table:
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if tag_lower == "tr":
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self._current_row = []
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return
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elif tag_lower in ("th", "td"):
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self._in_cell = True
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self._current_cell = []
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return
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elif tag_lower in ("thead", "tbody", "tfoot"):
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return # container only — rows/cells drive the output
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# Other tags inside cells (a/strong/em/code/br) fall through
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# to normal handling; _append_inline routes them to _current_cell.
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if tag_lower in ("p", "div", "section"):
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self._flush_block()
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elif tag_lower == "blockquote":
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self._flush_block()
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self._in_blockquote = True
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elif tag_lower == "br":
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self._append_inline("\n")
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elif tag_lower in ("h1", "h2", "h3", "h4", "h5", "h6"):
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self._flush_block()
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self._heading_level = int(tag_lower[1])
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elif tag_lower == "pre":
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self._flush_block()
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self._in_pre = True
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self._pre_content = []
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elif tag_lower == "code":
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# Inline code. <pre><code> is handled by the pre path, which
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# captures raw text verbatim — so only emit backticks when
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# we're NOT inside a pre block.
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if not self._in_pre:
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self._append_inline("`")
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elif tag_lower in ("ul", "ol"):
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self._list_stack.append([tag_lower, 0])
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elif tag_lower == "li":
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self._flush_block()
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depth = max(0, len(self._list_stack) - 1)
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self._pending_indent = " " * depth
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if self._list_stack and self._list_stack[-1][0] == "ol":
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self._list_stack[-1][1] += 1
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marker = f"{self._list_stack[-1][1]}. "
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else:
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marker = "- "
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self._block_buffer = marker
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self._block_empty = False
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elif tag_lower == "dt":
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self._flush_block()
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self._block_buffer = "**"
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self._block_empty = False
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elif tag_lower == "dd":
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self._flush_block()
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self._pending_indent = " "
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self._block_buffer = ""
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self._block_empty = True
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elif tag_lower == "a":
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self._in_link = True
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self._link_href = attrs_dict.get("href", "")
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self._link_text = []
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elif tag_lower in ("strong", "b"):
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self._append_inline("**")
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elif tag_lower in ("em", "i"):
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self._append_inline("*")
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elif tag_lower == "img":
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alt = attrs_dict.get("alt", "")
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src = attrs_dict.get("src", "")
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if alt or src:
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self._append_inline(f"")
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def handle_endtag(self, tag):
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tag_lower = tag.lower()
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if self._skip_depth > 0:
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self._skip_depth -= 1
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return
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if tag_lower == "pre":
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self._in_pre = False
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code = "\n".join(self._pre_content)
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self._output.append(f"```\n{code}\n```")
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self._pre_content = []
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self._block_empty = True
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elif tag_lower in ("h1", "h2", "h3", "h4", "h5", "h6"):
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prefix = "#" * self._heading_level
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self._output.append(f"\n{prefix} {self._block_buffer.strip()}\n")
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self._block_buffer = ""
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self._heading_level = 0
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self._block_empty = True
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elif tag_lower in ("th", "td"):
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# Collapse cell content to a single line (newlines from <br>
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# would break the GFM table row). Pipe chars are escaped to
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# avoid prematurely terminating cells.
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cell_text = " ".join(self._current_cell).strip()
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cell_text = re.sub(r'\s+', ' ', cell_text)
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cell_text = cell_text.replace("|", "\\|")
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if self._current_row is not None:
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self._current_row.append(cell_text)
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self._in_cell = False
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||
self._current_cell = None
|
||
elif tag_lower == "tr":
|
||
if self._current_row is not None:
|
||
is_header = False # GFM doesn't distinguish; first row is header
|
||
self._table_rows.append((self._current_row, is_header))
|
||
self._current_row = None
|
||
elif tag_lower == "table":
|
||
self._emit_table()
|
||
self._in_table = False
|
||
self._table_rows = []
|
||
self._current_row = None
|
||
self._current_cell = None
|
||
self._in_cell = False
|
||
elif tag_lower == "blockquote":
|
||
self._flush_block()
|
||
self._in_blockquote = False
|
||
self._output.append("")
|
||
elif tag_lower in ("p", "div", "section"):
|
||
self._flush_block()
|
||
self._output.append("")
|
||
elif tag_lower in ("ul", "ol"):
|
||
if self._list_stack:
|
||
self._list_stack.pop()
|
||
self._output.append("")
|
||
elif tag_lower == "li":
|
||
self._flush_block()
|
||
elif tag_lower == "dt":
|
||
self._block_buffer = self._block_buffer.rstrip() + "**"
|
||
self._flush_block()
|
||
elif tag_lower == "dd":
|
||
self._flush_block()
|
||
elif tag_lower == "a":
|
||
if self._in_link:
|
||
link_text = " ".join("".join(self._link_text).split())
|
||
if link_text and self._link_href:
|
||
rendered = f"[{link_text}]({self._link_href})"
|
||
elif self._link_href:
|
||
rendered = f"<{self._link_href}>"
|
||
else:
|
||
rendered = ""
|
||
if self._in_cell:
|
||
self._current_cell.append(rendered)
|
||
else:
|
||
self._block_buffer += rendered
|
||
self._block_empty = False
|
||
self._in_link = False
|
||
self._link_href = None
|
||
self._link_text = []
|
||
elif tag_lower == "code":
|
||
if not self._in_pre:
|
||
self._append_inline("`")
|
||
elif tag_lower in ("strong", "b"):
|
||
self._append_inline("**")
|
||
elif tag_lower in ("em", "i"):
|
||
self._append_inline("*")
|
||
|
||
def handle_data(self, data):
|
||
if self._skip_depth > 0:
|
||
return
|
||
if self._in_pre:
|
||
self._pre_content.append(data)
|
||
elif self._in_cell:
|
||
self._current_cell.append(data)
|
||
elif self._in_link:
|
||
self._link_text.append(data)
|
||
else:
|
||
# Don't strip — let _flush_block normalize whitespace
|
||
if data.strip(): # only skip purely whitespace nodes
|
||
self._block_buffer += data
|
||
self._block_empty = False
|
||
|
||
def get_markdown(self) -> str:
|
||
self._flush_block()
|
||
# Emit a table if one was left open (malformed HTML)
|
||
if self._in_table and self._table_rows:
|
||
self._emit_table()
|
||
text = "\n".join(self._output)
|
||
text = re.sub(r"\n{3,}", "\n\n", text)
|
||
return text.strip()
|
||
|
||
|
||
def html_to_markdown(html_content: str) -> str:
|
||
"""Convert HTML to Markdown using tree-based parser."""
|
||
# Quick strip of scripts/styles first
|
||
html_content = re.sub(r'<script[^>]*>.*?</script>', '', html_content,
|
||
flags=re.DOTALL | re.IGNORECASE)
|
||
html_content = re.sub(r'<style[^>]*>.*?</style>', '', html_content,
|
||
flags=re.DOTALL | re.IGNORECASE)
|
||
|
||
converter = MarkdownConverter()
|
||
converter.feed(html_content)
|
||
return converter.get_markdown()
|
||
|
||
|
||
# ----- HTTP Fetch -----
|
||
# RETRY_BACKOFF_BASE, FALLBACK_UAS, detect_charset and is_retryable_error are
|
||
# imported from common.py (shared with search.py for a consistent retry policy).
|
||
#
|
||
# v2.0.0 改进：
|
||
# * 模块级 requests.Session 复用连接池 + cookie，减少 TLS 握手开销
|
||
# * 超时分离 (connect, read) 元组，避免大页面下载中途超时浪费已建连接
|
||
# * 集成 build_browser_headers() 发送完整浏览器指纹
|
||
# * 遵守 Retry-After header，避免盲目重试触发更严厉限流
|
||
# * compute_backoff_delay() 带封顶，避免高重试次数卡死进程
|
||
|
||
# 模块级 Session：复用 TCP 连接池、TLS 会话、cookie。
|
||
# 仅在 requests 可用时启用；stdlib 路径不受益但功能完整。
|
||
_session = None
|
||
|
||
|
||
def _get_session():
|
||
"""获取（惰性创建）模块级 requests.Session。
|
||
|
||
Session 复用带来：
|
||
* HTTP Keep-Alive 连接池（同站点多页面只握手一次）
|
||
* Cookie 持久化（某些站点登录态/反爬 cookie 自动携带）
|
||
* TLS 会话恢复（session resumption，节省 1-RTT）
|
||
|
||
单元测试可通过 ``_reset_session()`` 重置后用 ``_HAS_REQUESTS=False``
|
||
强制走 stdlib 路径。
|
||
"""
|
||
global _session
|
||
if _session is None and _HAS_REQUESTS:
|
||
_session = _requests.Session()
|
||
# 配置连接池：每主机最多 10 连接，总最多 20 连接
|
||
adapter = _requests.adapters.HTTPAdapter(
|
||
pool_connections=10, pool_maxsize=10, max_retries=0,
|
||
)
|
||
_session.mount("http://", adapter)
|
||
_session.mount("https://", adapter)
|
||
return _session
|
||
|
||
|
||
def _reset_session() -> None:
|
||
"""关闭并重置模块级 Session。测试用。"""
|
||
global _session
|
||
if _session is not None:
|
||
try:
|
||
_session.close()
|
||
except Exception:
|
||
pass
|
||
_session = None
|
||
|
||
|
||
class _NoRedirectHandler(urllib.request.HTTPRedirectHandler):
|
||
"""urllib handler that returns the 3xx response instead of following it."""
|
||
|
||
def http_error_302(self, req, fp, code, msg, headers):
|
||
return fp
|
||
|
||
http_error_301 = http_error_303 = http_error_307 = http_error_308 = http_error_302
|
||
|
||
|
||
FetchResult = namedtuple(
|
||
"FetchResult",
|
||
["content", "content_type", "final_url", "truncated", "user_agent"],
|
||
)
|
||
|
||
|
||
def fetch_url(url: str, timeout=15, user_agent: str = None,
|
||
encoding: str = None, auth_headers: dict = None,
|
||
max_retries: int = 3, max_size: int = None,
|
||
allow_redirects: bool = True,
|
||
referer: str = None) -> "FetchResult":
|
||
"""Fetch a URL with retry, encoding detection, UA fallback, and optional size limit.
|
||
|
||
Returns a :class:`FetchResult` namedtuple with fields:
|
||
``content`` (str), ``content_type`` (str), ``final_url`` (str),
|
||
``truncated`` (bool — True if ``max_size`` cut the response short),
|
||
``user_agent`` (str — the UA string that succeeded; useful for logging
|
||
whether a fallback UA was needed).
|
||
|
||
max_size=None means unlimited (full page). Set to e.g. 5242880 for a 5MB cap.
|
||
allow_redirects=False stops the client from following HTTP 3xx redirects.
|
||
|
||
v2.0.0 改进：
|
||
* ``timeout`` 支持标量（向后兼容）或 ``(connect, read)`` 元组；
|
||
标量会被转换为 ``(timeout, timeout*2)`` 分离建连和读超时
|
||
* ``referer`` 参数：设置 Referer 头，伪装来自搜索引擎的流量
|
||
* 浏览器指纹头：通过 build_browser_headers() 发送完整 Sec-* 头
|
||
* 确定性 UA：通过 get_ua_for_domain() 为同域名固定 UA
|
||
* Retry-After：429/503 响应读取 Retry-After header 作为最小重试延迟
|
||
* 退避封顶：compute_backoff_delay() 上限 60s
|
||
* Session 复用：requests 路径复用模块级 Session
|
||
"""
|
||
# 超时归一化：标量 → (connect, read) 元组
|
||
if isinstance(timeout, (int, float)):
|
||
connect_timeout = min(float(timeout), 10.0) # 建连不超过 10s
|
||
read_timeout = float(timeout)
|
||
timeout_tuple = (connect_timeout, read_timeout)
|
||
else:
|
||
timeout_tuple = timeout # 已是元组，原样使用
|
||
|
||
# 确定性 UA 选择：同域名固定 UA
|
||
effective_ua = get_ua_for_domain(url, user_agent)
|
||
|
||
last_error = None
|
||
# UA 轮换池：首次用 effective_ua，后续重试轮换其他 UA
|
||
user_agents = [effective_ua] + [ua for ua in FALLBACK_UAS if ua != effective_ua]
|
||
|
||
for attempt in range(max_retries + 1):
|
||
# 同一域名内 UA 固定；仅在重试失败后才换（避免会话内突变）
|
||
# 但当退避原因可能是 UA 被屏蔽（403）时，必须换 UA
|
||
ua = user_agents[min(attempt, len(user_agents) - 1)]
|
||
|
||
# 构造完整浏览器头（v2.0.0 核心）
|
||
headers = build_browser_headers(ua, referer=referer, accept_html=True)
|
||
if auth_headers:
|
||
headers.update(auth_headers)
|
||
|
||
try:
|
||
if _HAS_REQUESTS:
|
||
session = _get_session()
|
||
resp = session.get(url, timeout=timeout_tuple, headers=headers,
|
||
allow_redirects=allow_redirects, stream=True)
|
||
# stream=True holds the socket open; must close explicitly,
|
||
# including on raise_for_status() / max_size break / decode
|
||
# errors — otherwise the connection leaks back to the pool
|
||
# and long-running agents exhaust ports.
|
||
try:
|
||
# 429/503：读取 Retry-After，作为最小重试延迟
|
||
if resp.status_code in (429, 503) and attempt < max_retries:
|
||
retry_after_raw = resp.headers.get("Retry-After", "")
|
||
retry_after_sec = parse_retry_after(retry_after_raw)
|
||
resp.close()
|
||
delay = max(retry_after_sec,
|
||
compute_backoff_delay(attempt))
|
||
logger.info(f" Fetch retry {attempt+1}/{max_retries} "
|
||
f"(HTTP {resp.status_code}, Retry-After={retry_after_sec:.1f}s) "
|
||
f"in {delay:.1f}s")
|
||
time.sleep(delay)
|
||
continue
|
||
|
||
resp.raise_for_status()
|
||
|
||
# Read: unlimited if max_size is None, chunked with limit otherwise
|
||
if max_size is None:
|
||
raw = resp.content
|
||
truncated = False
|
||
else:
|
||
chunks = []
|
||
total = 0
|
||
for chunk in resp.iter_content(chunk_size=65536, decode_unicode=False):
|
||
if chunk:
|
||
chunks.append(chunk)
|
||
total += len(chunk)
|
||
if total > max_size:
|
||
break
|
||
raw = b"".join(chunks)
|
||
truncated = total > max_size
|
||
|
||
if encoding:
|
||
content = raw.decode(encoding)
|
||
else:
|
||
charset = detect_charset(raw, resp.headers.get("Content-Type", ""))
|
||
try:
|
||
content = raw.decode(charset)
|
||
except (UnicodeDecodeError, LookupError):
|
||
content = raw.decode("utf-8", errors="replace")
|
||
|
||
return FetchResult(content, resp.headers.get("Content-Type", ""),
|
||
resp.url, truncated, ua)
|
||
finally:
|
||
resp.close()
|
||
|
||
# stdlib fallback
|
||
req = urllib.request.Request(url, headers=headers)
|
||
if allow_redirects:
|
||
_opener = urllib.request.urlopen(req, timeout=timeout_tuple[1])
|
||
else:
|
||
_opener = urllib.request.build_opener(_NoRedirectHandler).open(
|
||
req, timeout=timeout_tuple[1])
|
||
with _opener as resp:
|
||
if max_size is None:
|
||
raw = resp.read()
|
||
truncated = False
|
||
else:
|
||
chunks = []
|
||
total = 0
|
||
while True:
|
||
chunk = resp.read(65536)
|
||
if not chunk:
|
||
break
|
||
chunks.append(chunk)
|
||
total += len(chunk)
|
||
if total > max_size:
|
||
break
|
||
raw = b"".join(chunks)
|
||
truncated = total > max_size
|
||
content_type = resp.headers.get("Content-Type", "")
|
||
final_url = resp.geturl()
|
||
|
||
if encoding:
|
||
charset = encoding
|
||
else:
|
||
charset = detect_charset(raw, content_type)
|
||
try:
|
||
content = raw.decode(charset)
|
||
except (UnicodeDecodeError, LookupError):
|
||
content = raw.decode("utf-8", errors="replace")
|
||
|
||
return FetchResult(content, content_type, final_url, truncated, ua)
|
||
|
||
except urllib.error.HTTPError as e:
|
||
last_error = e
|
||
# 429/503：读取 Retry-After（stdlib 路径）
|
||
if e.code in (429, 503) and attempt < max_retries:
|
||
retry_after_raw = e.headers.get("Retry-After", "") if e.headers else ""
|
||
retry_after_sec = parse_retry_after(retry_after_raw)
|
||
# HTTPError 本身是可读的响应对象（fp 已被 urllib 消费），
|
||
# 无需显式 close；直接进入退避。
|
||
delay = max(retry_after_sec, compute_backoff_delay(attempt))
|
||
logger.info(f" Fetch retry {attempt+1}/{max_retries} "
|
||
f"(HTTP {e.code}, Retry-After={retry_after_sec:.1f}s) "
|
||
f"in {delay:.1f}s")
|
||
time.sleep(delay)
|
||
continue
|
||
if is_retryable_error(e) and attempt < max_retries:
|
||
delay = compute_backoff_delay(attempt)
|
||
logger.info(f" Fetch retry {attempt+1}/{max_retries} ({e}) in {delay:.1f}s")
|
||
time.sleep(delay)
|
||
continue
|
||
raise RuntimeError(f"HTTP {e.code} for {url}") from e
|
||
except (urllib.error.URLError, OSError, TimeoutError) as e:
|
||
last_error = e
|
||
if attempt < max_retries:
|
||
delay = compute_backoff_delay(attempt)
|
||
logger.info(f" Fetch retry {attempt+1}/{max_retries} ({e}) in {delay:.1f}s")
|
||
time.sleep(delay)
|
||
continue
|
||
raise RuntimeError(f"Request failed for {url}: {e}") from e
|
||
except Exception as e:
|
||
# requests backend: retry only on connection errors (no response)
|
||
# or transient 429/5xx; do NOT retry permanent errors like 404.
|
||
if _HAS_REQUESTS and isinstance(e, _requests.exceptions.RequestException):
|
||
last_error = e
|
||
status = getattr(getattr(e, "response", None), "status_code", None)
|
||
# 429/503 with Retry-After
|
||
if status in (429, 503) and attempt < max_retries:
|
||
resp_obj = getattr(e, "response", None)
|
||
retry_after_raw = ""
|
||
if resp_obj is not None:
|
||
retry_after_raw = resp_obj.headers.get("Retry-After", "")
|
||
retry_after_sec = parse_retry_after(retry_after_raw)
|
||
if resp_obj is not None:
|
||
resp_obj.close()
|
||
delay = max(retry_after_sec, compute_backoff_delay(attempt))
|
||
logger.info(f" Fetch retry {attempt+1}/{max_retries} "
|
||
f"(HTTP {status}, Retry-After={retry_after_sec:.1f}s) "
|
||
f"in {delay:.1f}s")
|
||
time.sleep(delay)
|
||
continue
|
||
if (status is None or status in RETRYABLE_STATUS) and attempt < max_retries:
|
||
delay = compute_backoff_delay(attempt)
|
||
logger.info(f" Fetch retry {attempt+1}/{max_retries} ({e}) in {delay:.1f}s")
|
||
time.sleep(delay)
|
||
continue
|
||
raise RuntimeError(f"Request failed for {url}: {e}") from e
|
||
|
||
raise RuntimeError(f"All {max_retries+1} attempts failed for {url}: {last_error}") from last_error
|
||
|
||
|
||
# ----- Main -----
|
||
|
||
def main():
|
||
parser = argparse.ArgumentParser(
|
||
description="Fetch a web page and extract readable content",
|
||
formatter_class=argparse.RawDescriptionHelpFormatter,
|
||
epilog=f"""searxng-cli v{VERSION}
|
||
|
||
Examples:
|
||
%(prog)s -u https://example.com extract clean text
|
||
%(prog)s -u https://example.com -e html raw HTML
|
||
%(prog)s -u https://example.com -e markdown markdown conversion
|
||
%(prog)s -u https://example.com -o page.txt save to file
|
||
%(prog)s -u https://example.cn -e text --encoding gbk force charset
|
||
""",
|
||
)
|
||
parser.add_argument("--url", "-u", required=True, help="URL to fetch")
|
||
parser.add_argument("--extract", "-e", choices=["text", "html", "markdown"],
|
||
default="text", help="Extraction mode (default: text)")
|
||
parser.add_argument("--timeout", "-t", type=int, default=15,
|
||
help="Request timeout in seconds (default: 15)")
|
||
parser.add_argument("--retries", type=int, default=3,
|
||
help="Max retries on transient errors (default: 3)")
|
||
parser.add_argument("--max-size", type=int, default=None, metavar="BYTES",
|
||
help="Max page size in bytes (default: unlimited). Set to 5242880 for 5MB cap.")
|
||
parser.add_argument("--user-agent", default=None,
|
||
help="Custom User-Agent header")
|
||
parser.add_argument("--encoding", default=None,
|
||
help="Force charset for decoding (e.g. gbk, shift_jis)")
|
||
parser.add_argument("--no-redirect", action="store_true",
|
||
help="Do not follow HTTP redirects")
|
||
parser.add_argument("--no-fallback", action="store_true",
|
||
help="Disable Wayback Machine fallback (v2.1.0). "
|
||
"By default, 403/404/timeout automatically retries "
|
||
"via web.archive.org. Hard-blocked domains "
|
||
"(baike.baidu.com, zhihu.com, etc.) always get "
|
||
"Wayback priority.")
|
||
parser.add_argument("--referer", default=None, metavar="URL",
|
||
help="Set Referer header (e.g. https://www.google.com/) to "
|
||
"disguise traffic source. v2.0.0 anti-bot measure.")
|
||
parser.add_argument("--proxy", default=None, metavar="URL",
|
||
help="HTTP/HTTPS proxy URL (e.g. http://corp-proxy:8080). "
|
||
"Respects existing HTTP_PROXY/HTTPS_PROXY env vars when omitted.")
|
||
parser.add_argument("--output", "-o", default=None,
|
||
help="Save to file instead of stdout")
|
||
parser.add_argument("--auth-bearer", default=None, metavar="TOKEN",
|
||
help="Authorization: Bearer <TOKEN> for authenticated endpoints")
|
||
parser.add_argument("--auth-bearer-file", default=None, metavar="FILE",
|
||
help="Read Bearer token from a file (first non-empty, non-# line). "
|
||
"Avoids leaving tokens in shell history.")
|
||
parser.add_argument("--auth-basic", default=None, metavar="USER:PASS",
|
||
help="Authorization: Basic base64(user:pass) for authenticated endpoints")
|
||
parser.add_argument("--auth-basic-file", default=None, metavar="FILE",
|
||
help="Read basic auth 'user:pass' from a file (first non-empty, non-# line). "
|
||
"Avoids leaving passwords in shell history. "
|
||
"Env var SEARXNG_BASIC_AUTH is also honored.")
|
||
parser.add_argument("--verbose", "-v", action="store_true", default=False,
|
||
help="Verbose output: show debug-level diagnostics on stderr")
|
||
parser.add_argument("--quiet", action="store_true", default=False,
|
||
help="Quiet output: suppress progress messages on stderr; "
|
||
"only warnings and errors are shown")
|
||
parser.add_argument("--version", action="version", version=f"searxng-cli v{VERSION}")
|
||
|
||
args = parser.parse_args()
|
||
setup_logging(verbose=args.verbose, quiet=args.quiet)
|
||
force_utf8_stdout() # Windows: prevent GBK crash on non-ASCII chars
|
||
|
||
if not args.url.startswith(("http://", "https://")):
|
||
logger.error("Error: URL must start with http:// or https://")
|
||
sys.exit(1)
|
||
|
||
# Apply proxy via env vars so both urllib and requests honor it.
|
||
if args.proxy:
|
||
apply_proxy(args.proxy)
|
||
logger.info(f"Proxy: {args.proxy}")
|
||
|
||
try:
|
||
bearer_token = resolve_auth_bearer(args.auth_bearer, args.auth_bearer_file)
|
||
basic_auth = resolve_auth_basic(args.auth_basic, args.auth_basic_file)
|
||
except RuntimeError as e:
|
||
logger.error(f"Error: {e}")
|
||
sys.exit(1)
|
||
auth_headers = build_auth_headers(
|
||
bearer_token=bearer_token,
|
||
basic_auth=basic_auth,
|
||
)
|
||
if auth_headers:
|
||
auth_type = "Bearer" if bearer_token else "Basic"
|
||
logger.info(f"Auth: {auth_type} ***")
|
||
|
||
# v2.1.0: 被墙站点提示
|
||
fallback_enabled = not args.no_fallback
|
||
hard_blocked = is_hard_blocked_domain(args.url)
|
||
if hard_blocked:
|
||
logger.info(f"Hard-blocked domain detected — Wayback fallback "
|
||
f"will be prioritized if main fetch fails")
|
||
|
||
try:
|
||
result = fetch_url(
|
||
args.url, timeout=args.timeout, user_agent=args.user_agent,
|
||
encoding=args.encoding, auth_headers=auth_headers,
|
||
max_retries=args.retries, max_size=args.max_size,
|
||
allow_redirects=not args.no_redirect,
|
||
referer=args.referer,
|
||
)
|
||
content, content_type, final_url = (
|
||
result.content, result.content_type, result.final_url,
|
||
)
|
||
except Exception as e:
|
||
# 诊断信息增强：从 __cause__ 链中提取 HTTP 状态码、原始异常类型，
|
||
# 让 AI Agent 能程序化判断失败原因（404 vs 403 vs DNS 失败等），
|
||
# 而不是只看到一句 "HTTP 404 for ..."。
|
||
cause = e.__cause__
|
||
status_code = None
|
||
cause_type = type(cause).__name__ if cause else type(e).__name__
|
||
# urllib HTTPError 有 .code 属性；requests HTTPError 有 .response.status_code
|
||
if cause is not None:
|
||
status_code = (getattr(cause, "code", None) or
|
||
getattr(getattr(cause, "response", None), "status_code", None))
|
||
if status_code is None:
|
||
# 最后一道兜底：从异常消息里提取 "HTTP NNN" 模式
|
||
m = re.search(r'HTTP (\d{3})', str(e))
|
||
if m:
|
||
status_code = int(m.group(1))
|
||
diag_parts = [f"Error: {e}"]
|
||
if status_code is not None:
|
||
diag_parts.append(f"status_code={status_code}")
|
||
diag_parts.append(f"cause={cause_type}")
|
||
diag_parts.append(f"url={args.url}")
|
||
if args.no_redirect:
|
||
diag_parts.append("redirects=disabled")
|
||
logger.error(" | ".join(diag_parts))
|
||
|
||
# v2.1.0: Wayback Machine 兜底
|
||
# 触发条件：兜底启用 + (错误可恢复 OR 命中被墙站点)
|
||
error_msg = str(e) if str(e) else e.__class__.__name__
|
||
if fallback_enabled and (should_try_wayback(error_msg) or hard_blocked):
|
||
wayback_url = build_wayback_url(args.url)
|
||
wb_timeout = min(args.timeout, 10) # Wayback 独立超时，不阻塞
|
||
logger.info(f"[FALLBACK] Trying Wayback Machine: {wayback_url[:70]}")
|
||
try:
|
||
wb_result = fetch_url(
|
||
wayback_url, timeout=wb_timeout,
|
||
user_agent=args.user_agent, encoding=args.encoding,
|
||
auth_headers=None, # Wayback 不需要原始站点的认证
|
||
max_retries=min(args.retries, 2),
|
||
max_size=args.max_size,
|
||
allow_redirects=True,
|
||
)
|
||
content, content_type, final_url = (
|
||
wb_result.content, wb_result.content_type,
|
||
wb_result.final_url,
|
||
)
|
||
logger.info(f"[FALLBACK] Wayback recovery successful "
|
||
f"({len(content)} chars)")
|
||
except Exception as wb_e:
|
||
logger.error(f"[FALLBACK] Wayback also failed: {wb_e}")
|
||
sys.exit(1)
|
||
else:
|
||
sys.exit(1)
|
||
|
||
if final_url != args.url:
|
||
logger.info(f"Redirected to: {final_url}")
|
||
|
||
is_html = ("html" in content_type.lower() or
|
||
content.strip().startswith("<!") or
|
||
content.strip().startswith("<htm"))
|
||
|
||
if args.extract == "html":
|
||
output = content
|
||
elif args.extract == "markdown":
|
||
output = html_to_markdown(content) if is_html else content
|
||
else: # text
|
||
output = extract_text(content) if is_html else content
|
||
|
||
# Quality check (threshold: 500 chars)
|
||
if args.extract == "text" and len(output.strip()) < 500 and is_html:
|
||
logger.warning(f"Warning: extracted text is very short ({len(output.strip())} chars). "
|
||
"The page may be JS-heavy or use anti-bot protection.")
|
||
|
||
if args.output:
|
||
with open(args.output, "w", encoding="utf-8") as f:
|
||
f.write(output)
|
||
logger.info(f"Saved {len(output)} chars to {args.output}")
|
||
else:
|
||
print(output)
|
||
|
||
|
||
if __name__ == "__main__":
|
||
main()
|