TXT to EPUB Converter

A powerful Python library for converting plain text files (.txt) to professional EPUB eBooks with intelligent chapter detection and AI-enhanced structure analysis.

中文文档 | English

✨ Features

• 📚 Intelligent Chapter Detection: Automatically identifies hierarchical structure (volumes, chapters, sections) using pattern matching
• 🤖 AI-Enhanced Parsing (Optional): Integrates with OpenAI-compatible LLMs for improved chapter title generation and structure analysis
• 🎯 Resume Support: Built-in checkpoint mechanism allows resuming interrupted conversions
• 🌍 Multi-Language Support: Handles both Chinese (GB18030, GBK, UTF-8) and English text with automatic encoding detection
• 💧 Watermark Support: Optional watermark text for copyright protection
• ✅ Content Validation: Automatic word count validation ensures conversion integrity
• ⚡ Progress Tracking: Real-time progress bar with detailed status updates
• 🎨 Professional Formatting: Clean, readable EPUB output with proper CSS styling

🚀 Installation

Install from PyPI (Recommended)

pip install txt-to-epub-converter

Install from Source

git clone https://github.com/yourusername/txt-to-epub-converter.git
cd txt-to-epub-converter
pip install -e .

Optional Dependencies

For AI-enhanced parsing (requires OpenAI-compatible API):

pip install txt-to-epub-converter[ai]

For development:

pip install txt-to-epub-converter[dev]

📖 Quick Start

Basic Usage

from txt_to_epub import txt_to_epub

# Simple conversion
result = txt_to_epub(
    txt_file="my_novel.txt",
    epub_file="output/my_novel.epub",
    title="My Novel",
    author="Author Name"
)

print(f"Conversion completed: {result['output_file']}")
print(f"Chapters: {result['chapters_count']}")
print(f"Validation: {'✓ Passed' if result['validation_passed'] else '✗ Failed'}")

Advanced Configuration

from txt_to_epub import txt_to_epub, ParserConfig

# Custom configuration
config = ParserConfig(
    # Chapter detection patterns
    chapter_patterns=[
        r'^第[0-9零一二三四五六七八九十百千]+章\s+.+$',  # Chinese: 第1章 标题
        r'^Chapter\s+\d+[:\s]+.+$'                      # English: Chapter 1: Title
    ],

    # Enable AI assistance
    enable_llm_assistance=True,
    llm_api_key="your-api-key",
    llm_base_url="https://api.openai.com/v1",
    llm_model="gpt-4o-mini",

    # Watermark
    enable_watermark=True,
    watermark_text="© 2026 Author Name. All rights reserved.",

    # Content filtering
    min_chapter_length=100,  # Minimum characters per chapter
    max_chapter_length=50000 # Maximum characters per chapter
)

# Convert with custom config
result = txt_to_epub(
    txt_file="my_book.txt",
    epub_file="output/my_book.epub",
    title="My Book",
    author="Author Name",
    cover_image="cover.jpg",  # Optional cover image
    config=config,
    enable_resume=True         # Enable checkpoint resume
)

🎯 Use Cases

Converting Web Novels

Perfect for converting downloaded web novels with standard chapter formatting:

from txt_to_epub import txt_to_epub

result = txt_to_epub(
    txt_file="web_novel.txt",
    epub_file="web_novel.epub",
    title="Epic Fantasy Novel",
    author="Web Author"
)

Converting Technical Documentation

Handles technical books with hierarchical structure:

from txt_to_epub import txt_to_epub, ParserConfig

config = ParserConfig(
    volume_patterns=[r'^Part\s+\d+[:\s]+.+$'],
    chapter_patterns=[r'^Chapter\s+\d+[:\s]+.+$'],
    section_patterns=[r'^\d+\.\d+\s+.+$']
)

result = txt_to_epub(
    txt_file="programming_guide.txt",
    epub_file="programming_guide.epub",
    title="Programming Guide",
    author="Tech Writer",
    config=config
)

Batch Conversion

Convert multiple files efficiently:

from txt_to_epub import txt_to_epub
from pathlib import Path

txt_files = Path("books").glob("*.txt")

for txt_file in txt_files:
    epub_file = f"output/{txt_file.stem}.epub"

    try:
        result = txt_to_epub(
            txt_file=str(txt_file),
            epub_file=epub_file,
            title=txt_file.stem.replace("_", " ").title(),
            author="Collection"
        )
        print(f"✓ Converted: {txt_file.name}")
    except Exception as e:
        print(f"✗ Failed: {txt_file.name} - {e}")

🛠️ Configuration Options

ParserConfig Parameters

Parameter	Type	Default	Description
chapter_patterns	List[str]	Built-in patterns	Regex patterns for chapter detection
volume_patterns	List[str]	Built-in patterns	Regex patterns for volume detection
section_patterns	List[str]	Built-in patterns	Regex patterns for section detection
min_chapter_length	int	50	Minimum characters per chapter
max_chapter_length	int	100000	Maximum characters per chapter
enable_llm_assistance	bool	False	Enable AI-enhanced parsing
llm_api_key	str	None	OpenAI-compatible API key
llm_base_url	str	OpenAI URL	API base URL
llm_model	str	"gpt-4o-mini"	Model name
enable_watermark	bool	False	Enable watermark
watermark_text	str	None	Watermark text

txt_to_epub() Parameters

Parameter	Type	Required	Description
txt_file	str	Yes	Input TXT file path
epub_file	str	Yes	Output EPUB file path
title	str	No	Book title (default: "My Book")
author	str	No	Author name (default: "Unknown")
cover_image	str	No	Cover image path (PNG/JPG)
config	ParserConfig	No	Custom configuration
show_progress	bool	No	Show progress bar (default: True)
enable_resume	bool	No	Enable checkpoint resume (default: False)

📊 Output Structure

The converter generates EPUB files with the following structure:

output.epub
├── Volume 1: Title
│   ├── Chapter 1: Title
│   ├── Chapter 2: Title
│   └── ...
├── Volume 2: Title
│   └── ...
└── Chapter N: Title (standalone chapters without volumes)
    ├── Section 1.1
    └── Section 1.2

🤖 AI-Enhanced Features

When enable_llm_assistance=True:

1. Smart Title Generation: Generates descriptive titles for chapters without clear titles
2. Table of Contents Detection: Removes redundant TOC sections automatically
3. Batch Processing: Processes multiple chapters in parallel for efficiency
4. Cost Tracking: Reports API usage and costs

Example with AI:

from txt_to_epub import txt_to_epub, ParserConfig

config = ParserConfig(
    enable_llm_assistance=True,
    llm_api_key="sk-...",
    llm_model="gpt-4o-mini"  # Fast and cost-effective
)

result = txt_to_epub(
    txt_file="novel.txt",
    epub_file="novel.epub",
    title="My Novel",
    author="Author",
    config=config
)

# AI usage stats are logged automatically

🔄 Resume Feature

The resume feature allows you to continue interrupted conversions:

result = txt_to_epub(
    txt_file="large_book.txt",
    epub_file="large_book.epub",
    title="Large Book",
    author="Author",
    enable_resume=True  # Enable checkpoint resume
)

If the conversion is interrupted (Ctrl+C, crash, etc.), simply run the same command again. The converter will:

• Detect the previous state file
• Verify the source file hasn't changed
• Resume from the last processed chapter
• Clean up the state file when complete

📝 Content Validation

Every conversion includes automatic validation:

=== Conversion Content Integrity Report ===
Source file: my_novel.txt
Original characters: 123,456
Converted characters: 123,450
Match rate: 99.99%

✓ Content integrity verification passed

🎨 Supported Text Formats

Chapter Title Formats

Chinese:

• 第一章 标题 (Traditional numbering)
• 第1章 标题 (Arabic numerals)
• 第001章 标题 (Zero-padded)
• Chapter 1: 标题 (Mixed)

English:

• Chapter 1: Title
• Chapter One: Title
• CHAPTER 1 - TITLE
• 1. Title

Volume/Book Formats

• 第一卷 标题 / 第1卷 标题 (Chinese)
• Volume 1: Title / Book 1: Title (English)
• Part I: Title (Roman numerals)

🧪 Testing

Run the test suite:

# Install dev dependencies
pip install -e .[dev]

# Run tests
pytest

# Run with coverage
pytest --cov=txt_to_epub --cov-report=html

📚 Examples

Check the examples directory for complete examples:

• basic_example.py - Simple conversion
• advanced_example.py - Custom configuration
• batch_convert.py - Batch processing
• README.md - Detailed example documentation

🤝 Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

Development Setup

# Clone repository
git clone https://github.com/yourusername/txt-to-epub-converter.git
cd txt-to-epub-converter

# Create virtual environment
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install development dependencies
pip install -e .[dev]

# Run tests
pytest

# Format code
black src/txt_to_epub

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• EbookLib - EPUB file generation
• chardet - Character encoding detection
• OpenAI - LLM assistance (optional)

📮 Support

• Issues: GitHub Issues
• Documentation: GitHub Wiki
• Changelog: CHANGELOG.md

🗺️ Roadmap

• Support for more eBook formats (MOBI, PDF)
• GUI application
• Command-line interface (CLI)
• Cloud service integration
• Enhanced AI features (style analysis, content summarization)
• Multi-language UI

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Made with ❤️ by the TXT to EPUB Converter Team

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