Initial commit: AI 知识库文档智能分块工具

parsers/csv_parser.py

@@ -0,0 +1,100 @@
+"""CSV 文件解析器，使用 charset-normalizer 检测编码 + csv.reader 读取，转换为 Markdown 表格"""
+
+import csv
+import io
+import os
+from typing import List
+
+from charset_normalizer import detect
+
+from exceptions import ParseError
+from parsers.base import BaseParser
+
+
+class CsvParser(BaseParser):
+    """CSV 文件解析器，将 CSV 数据转换为 Markdown 表格格式"""
+
+    def supported_extensions(self) -> List[str]:
+        return [".csv"]
+
+    def parse(self, file_path: str) -> str:
+        """
+        解析 CSV 文件，自动检测编码，转换为 Markdown 表格格式。
+
+        参考 MaxKB CsvSplitHandle.get_content() 核心逻辑：
+        读取文件字节 → charset_normalizer 检测编码 → 解码 → csv.reader 读取 → 构建 Markdown 表格
+
+        Markdown 表格格式：
+        | header1 | header2 | header3 |
+        | --- | --- | --- |
+        | data1 | data2 | data3 |
+
+        单元格处理：换行符替换为 <br>，管道符转义为 &#124;
+
+        Args:
+            file_path: 文件路径
+
+        Returns:
+            Markdown 表格格式的文本内容
+
+        Raises:
+            ParseError: 文件无法读取或编码检测失败时抛出
+        """
+        file_name = os.path.basename(file_path)
+
+        try:
+            with open(file_path, "rb") as f:
+                buffer = f.read()
+        except Exception as e:
+            raise ParseError(file_name, f"文件读取失败: {e}")
+
+        if len(buffer) == 0:
+            return ""
+
+        result = detect(buffer)
+        encoding = result.get("encoding")
+
+        if encoding is None:
+            raise ParseError(file_name, "无法检测文件编码")
+
+        try:
+            text = buffer.decode(encoding)
+        except Exception as e:
+            raise ParseError(file_name, f"编码解码失败 ({encoding}): {e}")
+
+        reader = csv.reader(io.StringIO(text))
+        rows = list(reader)
+
+        if not rows:
+            return ""
+
+        header = rows[0]
+        if not header:
+            return ""
+
+        lines = []
+
+        # Header row
+        header_cells = [self._escape_cell(cell) for cell in header]
+        lines.append("| " + " | ".join(header_cells) + " |")
+
+        # Separator row
+        lines.append("| " + " | ".join(["---"] * len(header)) + " |")
+
+        # Data rows
+        for row in rows[1:]:
+            # Pad or truncate row to match header length
+            padded = row + [""] * (len(header) - len(row))
+            cells = [self._escape_cell(cell) for cell in padded[: len(header)]]
+            lines.append("| " + " | ".join(cells) + " |")
+
+        return "\n".join(lines) + "\n"
+
+    @staticmethod
+    def _escape_cell(cell: str) -> str:
+        """转义单元格内容：换行符替换为 <br>，管道符替换为 &#124;"""
+        cell = cell.replace("|", "&#124;")
+        cell = cell.replace("\r\n", "<br>")
+        cell = cell.replace("\n", "<br>")
+        cell = cell.replace("\r", "<br>")
+        return cell