• 新增增强版PDF解析器,基于ChatGPT5策略使用文本层解析 • 实现混合PDF拆分器,优先文本层解析,OCR作为备份 • 添加数学符号选项修复功能,解决选择题空选项问题 • 性能提升:0.01秒vs29秒(2900倍),22+题目vs6题目(3.5倍) • 更新前端拆分界面,增加错误处理和用户体验优化 • 扩展数据库架构支持OCR相关字段 • 统一前后端配置管理,修复硬编码URL问题 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
442 lines
15 KiB
Python
442 lines
15 KiB
Python
"""
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基于PDF文本层的智能题目解析器
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借鉴ChatGPT的策略:直接提取PDF文本层,避免OCR误差
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"""
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import re
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import json
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import time
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from typing import List, Dict, Tuple, Optional
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import fitz # PyMuPDF
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import pdfplumber
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from dataclasses import dataclass
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@dataclass
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class Question:
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section: str
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qno: str
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type: str
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stem: str
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options: Dict[str, str]
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page_start: int
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page_end: int
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confidence: float = 1.0
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class PDFTextParser:
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def __init__(self):
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# 大题分区正则
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self.section_patterns = [
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re.compile(r'^\s*[((]?([一二三四五六七八九十]{1,3})[、.)]\s*(\S*题)', re.MULTILINE),
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re.compile(r'^\s*(\d+)\s*[、.]\s*(\S*题)', re.MULTILINE),
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]
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# 题号正则 - 支持多种格式
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self.question_patterns = [
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re.compile(r'^\s*(?:第\s*)?([0-9]{1,3}|[一二三四五六七八九十]{1,3})\s*[.)]'),
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re.compile(r'^\s*([0-9]{1,3})\s*[.、]\s*'),
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re.compile(r'^\s*\(([0-9]{1,3})\)\s*'),
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re.compile(r'^\s*(([0-9]{1,3}))\s*'),
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]
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# 选项正则
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self.option_patterns = [
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re.compile(r'^\s*([A-H])\s*[.)]\s*(.*)'),
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re.compile(r'^\s*(([A-H]))\s*(.*)'),
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re.compile(r'^\s*\(([A-H])\)\s*(.*)'),
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]
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# 中文数字转换
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self.chinese_numbers = {
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'一': '1', '二': '2', '三': '3', '四': '4', '五': '5',
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'六': '6', '七': '7', '八': '8', '九': '9', '十': '10',
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'十一': '11', '十二': '12', '十三': '13', '十四': '14', '十五': '15',
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'十六': '16', '十七': '17', '十八': '18', '十九': '19', '二十': '20'
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}
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def extract_text_with_pymupdf(self, pdf_path: str) -> List[Dict]:
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"""
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使用PyMuPDF提取文本(优先,速度快,顺序准确)
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"""
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try:
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doc = fitz.open(pdf_path)
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pages_text = []
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for page_num in range(len(doc)):
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page = doc[page_num]
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text = page.get_text()
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# 按行分割并保持行信息
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lines = []
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for line in text.split('\n'):
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line = line.strip()
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if line: # 过滤空行
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lines.append(line)
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pages_text.append({
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'page_num': page_num + 1,
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'lines': lines,
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'full_text': text
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})
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doc.close()
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print(f"✅ PyMuPDF提取完成: {len(pages_text)}页")
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return pages_text
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except Exception as e:
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print(f"❌ PyMuPDF提取失败: {e}")
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return []
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def extract_text_with_pdfplumber(self, pdf_path: str) -> List[Dict]:
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"""
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使用pdfplumber提取文本(备用,处理复杂布局)
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"""
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try:
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pages_text = []
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with pdfplumber.open(pdf_path) as pdf:
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for page_num, page in enumerate(pdf.pages):
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text = page.extract_text()
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if text:
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lines = []
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for line in text.split('\n'):
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line = line.strip()
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if line:
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lines.append(line)
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pages_text.append({
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'page_num': page_num + 1,
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'lines': lines,
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'full_text': text
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})
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print(f"✅ pdfplumber提取完成: {len(pages_text)}页")
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return pages_text
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except Exception as e:
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print(f"❌ pdfplumber提取失败: {e}")
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return []
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def extract_pdf_text(self, pdf_path: str) -> List[Dict]:
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"""
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智能文本提取:优先PyMuPDF,失败时回退pdfplumber
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"""
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print(f"🔄 开始PDF文本提取: {pdf_path}")
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start_time = time.time()
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# 优先使用PyMuPDF
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pages_text = self.extract_text_with_pymupdf(pdf_path)
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# 如果PyMuPDF失败或结果为空,回退到pdfplumber
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if not pages_text:
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print("⚠️ PyMuPDF结果为空,回退到pdfplumber")
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pages_text = self.extract_text_with_pdfplumber(pdf_path)
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print(f"⚡ 文本提取完成: 耗时{time.time() - start_time:.2f}秒")
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return pages_text
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def normalize_text(self, text: str) -> str:
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"""
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文本标准化:处理全角半角、中文数字等
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"""
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# 全角转半角
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text = text.replace('(', '(').replace(')', ')')
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text = text.replace('.', '.').replace('、', '.')
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text = text.replace(':', ':').replace(';', ';')
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# 去除多余空格
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text = re.sub(r'\s+', ' ', text).strip()
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return text
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def detect_sections(self, pages_text: List[Dict]) -> List[Dict]:
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"""
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检测大题分区(一、选择题,二、填空题等)
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"""
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sections = []
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current_section = None
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for page_data in pages_text:
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page_num = page_data['page_num']
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for line in page_data['lines']:
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normalized_line = self.normalize_text(line)
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# 检测分区标题
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for pattern in self.section_patterns:
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match = pattern.match(normalized_line)
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if match:
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section_num = match.group(1)
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section_name = match.group(2)
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# 转换中文数字
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if section_num in self.chinese_numbers:
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section_num = self.chinese_numbers[section_num]
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current_section = {
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'section_num': section_num,
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'section_name': section_name,
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'start_page': page_num,
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'start_line': normalized_line
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}
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sections.append(current_section)
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print(f"📚 检测到分区: {section_num}、{section_name} (第{page_num}页)")
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break
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return sections
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def convert_chinese_number(self, num_str: str) -> str:
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"""
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转换中文数字为阿拉伯数字
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"""
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if num_str in self.chinese_numbers:
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return self.chinese_numbers[num_str]
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return num_str
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def detect_question_number(self, line: str) -> Optional[str]:
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"""
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检测题号
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"""
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normalized_line = self.normalize_text(line)
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for pattern in self.question_patterns:
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match = pattern.match(normalized_line)
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if match:
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qno = match.group(1)
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# 转换中文数字
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qno = self.convert_chinese_number(qno)
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try:
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# 验证是否为合理的题号
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num = int(qno)
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if 1 <= num <= 100: # 假设题目数量在1-100之间
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return str(num)
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except ValueError:
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continue
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return None
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def detect_option(self, line: str) -> Optional[Tuple[str, str]]:
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"""
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检测选项(A、B、C、D等)
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"""
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normalized_line = self.normalize_text(line)
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for pattern in self.option_patterns:
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match = pattern.match(normalized_line)
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if match:
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option_letter = match.group(1)
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option_content = match.group(2).strip()
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return option_letter, option_content
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return None
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def parse_questions(self, pages_text: List[Dict]) -> List[Question]:
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"""
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解析题目:核心算法
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"""
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print("🔄 开始智能题目解析")
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start_time = time.time()
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questions = []
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current_question = None
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current_section = "未知"
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all_lines = []
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# 合并所有页面的行,保持页码信息
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for page_data in pages_text:
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for line in page_data['lines']:
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all_lines.append({
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'text': line,
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'page': page_data['page_num']
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})
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i = 0
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while i < len(all_lines):
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line_data = all_lines[i]
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line = line_data['text']
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page_num = line_data['page']
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# 检测分区
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for pattern in self.section_patterns:
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match = pattern.match(self.normalize_text(line))
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if match:
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section_name = match.group(2)
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current_section = section_name
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print(f"📚 进入分区: {section_name}")
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break
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# 检测题号
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qno = self.detect_question_number(line)
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if qno:
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# 保存上一题
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if current_question:
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questions.append(current_question)
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# 开始新题
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question_type = self.infer_question_type(current_section, line)
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current_question = Question(
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section=current_section,
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qno=qno,
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type=question_type,
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stem=line,
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options={},
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page_start=page_num,
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page_end=page_num
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)
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print(f"📝 题目{qno}: {line[:50]}...")
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elif current_question:
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# 检测选项
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option_result = self.detect_option(line)
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if option_result:
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option_letter, option_content = option_result
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current_question.options[option_letter] = option_content
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current_question.page_end = page_num
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else:
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# 继续当前题目内容
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if len(current_question.stem) < 1000: # 防止过长
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current_question.stem += ' ' + line
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current_question.page_end = page_num
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i += 1
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# 保存最后一题
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if current_question:
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questions.append(current_question)
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print(f"✅ 题目解析完成: {len(questions)}道题, 耗时{time.time() - start_time:.2f}秒")
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return questions
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def infer_question_type(self, section: str, line: str) -> str:
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"""
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推断题目类型
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"""
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if '选择' in section:
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return 'multiple_choice'
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elif '填空' in section:
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return 'fill_blank'
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elif '解答' in section or '计算' in section:
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return 'solve'
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elif '判断' in section:
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return 'true_false'
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else:
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# 根据内容推断
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if re.search(r'[A-D][.))]', line):
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return 'multiple_choice'
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elif '______' in line or '___' in line:
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return 'fill_blank'
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else:
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return 'unknown'
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def process_pdf(self, pdf_path: str) -> Dict:
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"""
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主处理函数
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"""
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total_start = time.time()
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print(f"🎯 开始基于文本层的PDF解析: {pdf_path}")
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try:
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# 1. 提取PDF文本
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pages_text = self.extract_pdf_text(pdf_path)
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if not pages_text:
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return {"success": False, "error": "PDF文本提取失败"}
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# 2. 解析题目
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questions = self.parse_questions(pages_text)
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# 3. 转换为API格式
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formatted_questions = []
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for q in questions:
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formatted_questions.append({
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'number': q.qno,
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'type': q.type,
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'text': q.stem,
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'options': q.options if q.options else None,
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'page': q.page_start,
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'bbox': [], # 文本层解析无bbox信息
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'confidence': q.confidence,
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'page_spans': list(range(q.page_start, q.page_end + 1)),
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'source_text': q.stem,
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'images': [],
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'auto_extracted': True,
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'section': q.section
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})
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total_time = time.time() - total_start
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print(f"🎉 文本层解析完成!总耗时: {total_time:.2f}秒")
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return {
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"success": True,
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"questions": formatted_questions,
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"total_time": total_time,
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"pages_processed": len(pages_text),
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"questions_found": len(formatted_questions),
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"stats": {
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"total_time": total_time,
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"pages_processed": len(pages_text),
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"questions_found": len(formatted_questions),
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"avg_time_per_page": total_time / len(pages_text) if pages_text else 0,
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"method": "text_layer_parsing"
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}
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}
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except Exception as e:
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print(f"❌ 文本层解析失败: {str(e)}")
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return {"success": False, "error": str(e)}
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def export_to_json(self, questions: List[Question], output_path: str):
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"""
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导出为JSON格式
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"""
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data = []
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for q in questions:
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data.append({
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'section': q.section,
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'qno': q.qno,
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'type': q.type,
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'stem': q.stem,
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'options': q.options,
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'page_start': q.page_start,
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'page_end': q.page_end,
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'confidence': q.confidence
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})
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with open(output_path, 'w', encoding='utf-8') as f:
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json.dump(data, f, ensure_ascii=False, indent=2)
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print(f"✅ JSON导出完成: {output_path}")
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# 测试函数
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def test_text_parser():
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"""
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测试文本解析器
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"""
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pdf_path = "/Users/brunogao/Downloads/深圳市八年级(上)期中数学试卷1.pdf"
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if not os.path.exists(pdf_path):
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print(f"❌ 测试文件不存在: {pdf_path}")
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return
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parser = PDFTextParser()
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result = parser.process_pdf(pdf_path)
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if result["success"]:
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print(f"""
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📊 文本层解析测试结果:
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- 总时间: {result['total_time']:.2f}秒
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- 页数: {result['pages_processed']}
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- 题目: {result['questions_found']}道
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- 方法: {result['stats']['method']}
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""")
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print("识别的题目:")
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for i, q in enumerate(result['questions'][:8]):
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options_str = f" 选项: {list(q.get('options', {}).keys())}" if q.get('options') else ""
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print(f"题目{q['number']} ({q['type']}): {q['text'][:60]}...{options_str}")
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else:
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print(f"❌ 测试失败: {result['error']}")
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if __name__ == "__main__":
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import os
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test_text_parser() |