feat: metagpt-Python-PDF-Feedback-UI-20260326

resources/system_design/20260326175651.md

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+## Implementation approach
+
+使用pypdf库实现PDF文件的读取和文本提取，该库安装简单、API直观，完全满足'尽量简单'的要求。程序通过Python标准库argparse接收命令行参数，支持指定PDF文件路径和可选的页码范围。异常处理使用Python内置异常机制，覆盖文件不存在、格式错误、权限不足等常见情况。整个程序只需一个主文件，依赖最小化。
+
+## File list
+
+- main.py
+
+## Data structures and interfaces
+
+
+classDiagram
+    class PDFOpener {
+        -str file_path
+        -int start_page
+        -int end_page
+        +__init__(file_path: str, start_page: int, end_page: int)
+        +open() PdfReader
+        +get_info(reader: PdfReader) dict
+        +extract_text(reader: PdfReader) list[str]
+        +display_info(info: dict) None
+        +display_text(texts: list[str]) None
+        +run() None
+    }
+    class Main {
+        +parse_args() argparse.Namespace
+        +main() None
+    }
+    Main --> PDFOpener : creates and uses
+
+
+## Program call flow
+
+
+sequenceDiagram
+    participant M as Main
+    participant AP as argparse
+    participant PO as PDFOpener
+    participant PR as PdfReader(pypdf)
+
+    M->>AP: parse_args()
+    AP-->>M: args(file_path, start_page, end_page)
+    M->>PO: __init__(file_path, start_page, end_page)
+    M->>PO: run()
+    PO->>PO: open()
+    PO->>PR: PdfReader(file_path)
+    PR-->>PO: reader
+    PO->>PO: get_info(reader)
+    PR-->>PO: info(num_pages, metadata)
+    PO->>PO: display_info(info)
+    PO-->>M: print info to console
+    PO->>PO: extract_text(reader)
+    loop for each page in range
+        PR-->>PO: page.extract_text()
+    end
+    PO->>PO: display_text(texts)
+    PO-->>M: print text to console
+
+
+## Anything UNCLEAR
+
+当前需求已较为清晰，按最简单的文本提取功能实现。程序仅支持文本内容提取和基本信息展示，不支持复制、搜索、保存等高级操作。若后续需要支持加密PDF的解密或表格提取，可考虑升级为pdfplumber或pymupdf库。
+