feat: 添加知乎问答支持

- zhihu_extractor.py:
  - 添加 URL_PATTERNS 支持 answer 和 question
  - 添加 _extract_answer_content() 方法提取知乎回答
  - 添加 _extract_question_content() 方法提取知乎问题

- zhihu_metadata.py:
  - 添加 extract_answer() 函数
  - 添加 extract_question() 函数
  - 更新命令行参数支持 answer/question 类型
  - 更新帮助文档

kb-zhihu-metadata/zhihu_extractor.py

@@ -80,6 +80,8 @@ class ZhihuPlaywrightExtractor:
     URL_PATTERNS = {
         'zvideo': r'zhihu\.com/zvideo/(\d+)',
         'zhuanlan': r'zhuanlan\.zhihu\.com/p/(\d+)',
+        'answer': r'zhihu\.com/question/\d+/answer/(\d+)',
+        'question': r'zhihu\.com/question/(\d+)',
     }
 
     def __init__(self, headless: bool = True, timeout: int = 30):
@@ -242,6 +244,115 @@ class ZhihuPlaywrightExtractor:
 
         return result
 
+    def _extract_answer_content(self) -> Dict[str, Any]:
+        """提取知乎回答内容"""
+        result = {
+            'type': 'answer',
+            'title': '',  # 问题标题
+            'question_id': '',
+            'answer_id': '',
+            'author': '',
+            'content': '',
+            'content_markdown': '',
+            'publish_time': '',
+            'vote_up': 0,
+        }
+
+        # 打印页面标题用于调试
+        page_title = self.browser.page.title()
+        print(f"页面标题: {page_title}")
+
+        # 提取问题标题
+        question_title_elem = self.browser.query_selector('.QuestionHeader-title')
+        if not question_title_elem:
+            question_title_elem = self.browser.query_selector('.QuestionHeader-content h1')
+        if question_title_elem:
+            result['title'] = self._extract_text_content(question_title_elem)
+
+        # 提取回答内容
+        content_elem = self.browser.query_selector('.RichText')
+        if not content_elem:
+            content_elem = self.browser.query_selector('.AnswerItem-richText')
+        if not content_elem:
+            content_elem = self.browser.query_selector('[class*="RichText"]')
+        if content_elem:
+            html_content = self._extract_html_content(content_elem)
+            result['content'] = html_content
+            result['content_markdown'] = self.markdown_converter.convert(html_content)
+
+        # 提取作者信息
+        author_elem = self.browser.query_selector('.AuthorInfo-name')
+        if author_elem:
+            result['author'] = self._extract_text_content(author_elem)
+
+        # 提取发布时间
+        time_elem = self.browser.query_selector('.AnswerItem-time')
+        if not time_elem:
+            time_elem = self.browser.query_selector('.ContentItem-time')
+        if time_elem:
+            result['publish_time'] = time_elem.get_attribute('data-tooltip') or self._extract_text_content(time_elem)
+
+        # 提取点赞数
+        vote_elem = self.browser.query_selector('.VoteButton--up .VoteButton-label')
+        if not vote_elem:
+            vote_elem = self.browser.query_selector('.VoteButton .Count')
+        if vote_elem:
+            vote_text = self._extract_text_content(vote_elem)
+            try:
+                result['vote_up'] = int(vote_text.replace(',', ''))
+            except (ValueError, AttributeError):
+                pass
+
+        return result
+
+    def _extract_question_content(self) -> Dict[str, Any]:
+        """提取知乎问题内容（包含所有回答）"""
+        result = {
+            'type': 'question',
+            'title': '',
+            'question_id': '',
+            'author': '',
+            'content': '',
+            'content_markdown': '',
+            'publish_time': '',
+            'answer_count': 0,
+        }
+
+        # 打印页面标题用于调试
+        page_title = self.browser.page.title()
+        print(f"页面标题: {page_title}")
+
+        # 提取问题标题
+        title_elem = self.browser.query_selector('.QuestionHeader-title')
+        if not title_elem:
+            title_elem = self.browser.query_selector('.QuestionHeader-content h1')
+        if title_elem:
+            result['title'] = self._extract_text_content(title_elem)
+
+        # 提取问题描述
+        desc_elem = self.browser.query_selector('.QuestionHeader-detail')
+        if not desc_elem:
+            desc_elem = self.browser.query_selector('.QuestionRichText')
+        if desc_elem:
+            html_content = self._extract_html_content(desc_elem)
+            result['content'] = html_content
+            result['content_markdown'] = self.markdown_converter.convert(html_content)
+
+        # 提取回答数量
+        answer_count_elem = self.browser.query_selector('.List-headerText span')
+        if answer_count_elem:
+            count_text = self._extract_text_content(answer_count_elem)
+            try:
+                # 提取数字
+                import re
+                match = re.search(r'(\d+)', count_text)
+                if match:
+                    result['answer_count'] = int(match.group(1))
+            except (ValueError, AttributeError):
+                pass
+
+        return result
+
     def extract(self, url: str) -> Optional[Dict[str, Any]]:
         """
         从 URL 提取知乎内容
@@ -288,6 +399,10 @@ class ZhihuPlaywrightExtractor:
                 result = self._extract_zvideo_content()
             elif url_type == 'zhuanlan':
                 result = self._extract_zhuanlan_content()
+            elif url_type == 'answer':
+                result = self._extract_answer_content()
+            elif url_type == 'question':
+                result = self._extract_question_content()
             else:
                 print(f"不支持的类型: {url_type}")
                 return None

kb-zhihu-metadata/zhihu_metadata.py

@@ -2,9 +2,11 @@
 """
 知乎元数据获取工具
 
-仅支持两种内容类型：
+支持以下内容类型：
 - zvideo: 知乎视频 (https://www.zhihu.com/zvideo/xxx)
 - zhuanlan: 知乎专栏文章 (https://zhuanlan.zhihu.com/p/xxx)
+- answer: 知乎回答 (https://www.zhihu.com/question/xxx/answer/yyy)
+- question: 知乎问题 (https://www.zhihu.com/question/xxx)
 """
 
 import argparse
@@ -51,6 +53,38 @@ def extract_zhuanlan(article_id: str, headless: bool = True) -> Dict[str, Any]:
     return _extract_metadata(url, "zhuanlan", headless)
 
 
+def extract_answer(answer_id: str, headless: bool = True) -> Dict[str, Any]:
+    """
+    获取知乎回答元数据
+
+    Args:
+        answer_id: 回答 ID (数字字符串)
+        headless: 是否使用无头浏览器
+
+    Returns:
+        回答元数据字典
+    """
+    # 回答需要构建包含问题ID的URL，但answer_id本身足以识别
+    # 使用一个占位符问题ID，因为提取器会从URL中提取answer_id
+    url = f"https://www.zhihu.com/question/0/answer/{answer_id}"
+    return _extract_metadata(url, "answer", headless)
+
+
+def extract_question(question_id: str, headless: bool = True) -> Dict[str, Any]:
+    """
+    获取知乎问题元数据
+
+    Args:
+        question_id: 问题 ID (数字字符串)
+        headless: 是否使用无头浏览器
+
+    Returns:
+        问题元数据字典
+    """
+    url = f"https://www.zhihu.com/question/{question_id}"
+    return _extract_metadata(url, "question", headless)
+
+
 def _extract_metadata(url: str, content_type: str, headless: bool) -> Dict[str, Any]:
     """
     内部函数：提取元数据
@@ -97,24 +131,28 @@ def main():
 支持的类型:
   zvideo   - 知乎视频 (https://www.zhihu.com/zvideo/123456)
   zhuanlan - 知乎专栏文章 (https://zhuanlan.zhihu.com/p/123456)
+  answer   - 知乎回答 (https://www.zhihu.com/question/xxx/answer/yyy)
+  question - 知乎问题 (https://www.zhihu.com/question/xxx)
 
 示例:
   python zhihu_metadata.py --id "123456" --type zvideo
   python zhihu_metadata.py --id "123456" --type zhuanlan
+  python zhihu_metadata.py --id "123456" --type answer
+  python zhihu_metadata.py --id "123456" --type question
         """
     )
 
     parser.add_argument(
         "--id", "-i",
         required=True,
-        help="知乎内容 ID (视频ID或文章ID)"
+        help="知乎内容 ID (视频ID/文章ID/回答ID/问题ID)"
     )
 
     parser.add_argument(
         "--type", "-t",
         required=True,
-        choices=["zvideo", "zhuanlan"],
+        choices=["zvideo", "zhuanlan", "answer", "question"],
-        help="内容类型: zvideo=视频, zhuanlan=专栏文章"
+        help="内容类型: zvideo=视频, zhuanlan=专栏文章, answer=回答, question=问题"
     )
 
     parser.add_argument(
@@ -135,8 +173,15 @@ def main():
     # 提取元数据
     if args.type == "zvideo":
         result = extract_zvideo(args.id, headless=args.headless)
-    else:  # zhuanlan
+    elif args.type == "zhuanlan":
         result = extract_zhuanlan(args.id, headless=args.headless)
+    elif args.type == "answer":
+        result = extract_answer(args.id, headless=args.headless)
+    elif args.type == "question":
+        result = extract_question(args.id, headless=args.headless)
+    else:
+        print(f"不支持的类型: {args.type}")
+        sys.exit(1)
 
     # 输出结果
     json_output = json.dumps(result, ensure_ascii=False, indent=2)