tzst

tzst is a next-generation Python library engineered for modern archive management, leveraging cutting-edge Zstandard compression to deliver superior performance, security, and reliability. Built exclusively for Python 3.12+, this enterprise-grade solution combines atomic operations, streaming efficiency, and a meticulously crafted API to redefine how developers handle .tzst/.tar.zst archives in production environments.

Features

• High Compression: Zstandard compression for excellent compression ratios and speed
• Tar Compatibility: Creates standard tar archives compressed with Zstandard
• Command Line Interface: Intuitive CLI with streaming support and comprehensive options
• Python API: Clean, Pythonic API for programmatic use
• Cross-Platform: Works on Windows, macOS, and Linux
• Multiple Extensions: Supports both .tzst and .tar.zst extensions
• Memory Efficient: Streaming mode for handling large archives with minimal memory usage
• Atomic Operations: Safe file operations with automatic cleanup on interruption
• Secure by Default: Uses the 'data' filter for maximum security during extraction
• Enhanced Error Handling: Clear error messages with helpful alternatives

Installation

From PyPI

pip install tzst

From Source

git clone https://github.com/xixu-me/tzst.git
cd tzst
pip install .

Development Installation

This project uses Hatch as the build system:

git clone https://github.com/xixu-me/tzst.git
cd tzst
pip install -e .[dev]

Alternatively, with Hatch installed:

hatch env create
hatch shell

Quick Start

Command Line Usage

Recommended: Use uvx tzst for running without installation and better performance. See uv documentation for details.

# Create an archive
tzst a archive.tzst file1.txt file2.txt directory/

# Extract an archive
tzst x archive.tzst

# List archive contents
tzst l archive.tzst

# Test archive integrity
tzst t archive.tzst

Python API Usage

from tzst import create_archive, extract_archive, list_archive

# Create an archive
create_archive("archive.tzst", ["file1.txt", "file2.txt", "directory/"])

# Extract an archive
extract_archive("archive.tzst", "output_directory/")

# List archive contents
contents = list_archive("archive.tzst", verbose=True)
for item in contents:
    print(f"{item['name']}: {item['size']} bytes")

Command Line Interface

Archive Operations

Create Archive

# Basic usage
tzst a archive.tzst file1.txt file2.txt

# With compression level (1-22, default: 3)
tzst a archive.tzst files/ -l 15

# Alternative commands
tzst add archive.tzst files/
tzst create archive.tzst files/

Extract Archive

# Extract with full directory structure
tzst x archive.tzst

# Extract to specific directory
tzst x archive.tzst -o output/

# Extract specific files
tzst x archive.tzst file1.txt dir/file2.txt

# Extract without directory structure (flat)
tzst e archive.tzst -o output/

# Use streaming mode for large archives
tzst x archive.tzst --streaming -o output/

List Contents

# Simple listing
tzst l archive.tzst

# Verbose listing with details
tzst l archive.tzst -v

# Use streaming mode for large archives
tzst l archive.tzst --streaming -v

Test Integrity

# Test archive integrity
tzst t archive.tzst

# Test with streaming mode
tzst t archive.tzst --streaming

Command Reference

Command	Aliases	Description	Streaming Support
a	add, create	Create or add to archive	N/A
x	extract	Extract with full paths	✓ --streaming
e	extract-flat	Extract without directory structure	✓ --streaming
l	list	List archive contents	✓ --streaming
t	test	Test archive integrity	✓ --streaming

CLI Options

• -v, --verbose: Enable verbose output
• -o, --output DIR: Specify output directory (extract commands)
• -l, --level LEVEL: Set compression level 1-22 (create command)
• --streaming: Enable streaming mode for memory-efficient processing
• --filter FILTER: Security filter for extraction (data/tar/fully_trusted)
• --no-atomic: Disable atomic file operations (not recommended)

Security Filters

# Extract with maximum security (default)
tzst x archive.tzst --filter data

# Extract with standard tar compatibility
tzst x archive.tzst --filter tar

# Extract with full trust (dangerous - only for trusted archives)
tzst x archive.tzst --filter fully_trusted

Security Filter Options:

• data (default): Most secure. Blocks dangerous files, absolute paths, and paths outside extraction directory
• tar: Standard tar compatibility. Blocks absolute paths and directory traversal
• fully_trusted: No security restrictions. Only use with completely trusted archives

Python API

TzstArchive Class

from tzst import TzstArchive

# Create a new archive
with TzstArchive("archive.tzst", "w", compression_level=5) as archive:
    archive.add("file.txt")
    archive.add("directory/", recursive=True)

# Read an existing archive
with TzstArchive("archive.tzst", "r") as archive:
    # List contents
    contents = archive.list(verbose=True)
    
    # Extract with security filter
    archive.extract("file.txt", "output/", filter="data")
    
    # Test integrity
    is_valid = archive.test()

# For large archives, use streaming mode
with TzstArchive("large_archive.tzst", "r", streaming=True) as archive:
    archive.extract(path="output/")

Important Limitations:

• Append Mode Not Supported: Create multiple archives or recreate the entire archive instead

Convenience Functions

create_archive()

from tzst import create_archive

# Create with atomic operations (default)
create_archive(
    archive_path="backup.tzst",
    files=["documents/", "photos/", "config.txt"],
    compression_level=10
)

extract_archive()

from tzst import extract_archive

# Extract with security (default: 'data' filter)
extract_archive("backup.tzst", "restore/")

# Extract specific files
extract_archive("backup.tzst", "restore/", members=["config.txt"])

# Flatten directory structure
extract_archive("backup.tzst", "restore/", flatten=True)

# Use streaming for large archives
extract_archive("large_backup.tzst", "restore/", streaming=True)

list_archive()

from tzst import list_archive

# Simple listing
files = list_archive("backup.tzst")

# Detailed listing
files = list_archive("backup.tzst", verbose=True)

# Streaming for large archives
files = list_archive("large_backup.tzst", streaming=True)

test_archive()

from tzst import test_archive

# Basic integrity test
if test_archive("backup.tzst"):
    print("Archive is valid")

# Test with streaming
if test_archive("large_backup.tzst", streaming=True):
    print("Large archive is valid")

Advanced Features

File Extensions

The library automatically handles file extensions with intelligent normalization:

• .tzst - Primary extension for tar+zstandard archives
• .tar.zst - Alternative standard extension
• Auto-detection when opening existing archives
• Automatic extension addition when creating archives

# These all create valid archives
create_archive("backup.tzst", files)      # Creates backup.tzst
create_archive("backup.tar.zst", files)  # Creates backup.tar.zst  
create_archive("backup", files)          # Creates backup.tzst
create_archive("backup.txt", files)      # Creates backup.tzst (normalized)

Compression Levels

Zstandard compression levels range from 1 (fastest) to 22 (best compression):

• Level 1-3: Fast compression, larger files
• Level 3 (default): Good balance of speed and compression
• Level 10-15: Better compression, slower
• Level 20-22: Maximum compression, much slower

Streaming Mode

Use streaming mode for memory-efficient processing of large archives:

Benefits:

• Significantly reduced memory usage
• Better performance for archives that don't fit in memory
• Automatic cleanup of resources

When to Use:

• Archives larger than 100MB
• Limited memory environments
• Processing archives with many large files

# Example: Processing a large backup archive
from tzst import extract_archive, list_archive, test_archive

large_archive = "backup_500gb.tzst"

# Memory-efficient operations
is_valid = test_archive(large_archive, streaming=True)
contents = list_archive(large_archive, streaming=True, verbose=True)
extract_archive(large_archive, "restore/", streaming=True)

Atomic Operations

All file creation operations use atomic file operations by default:

• Archives created in temporary files first, then atomically moved
• Automatic cleanup if process is interrupted
• No risk of corrupted or incomplete archives
• Cross-platform compatibility

# Atomic operations enabled by default
create_archive("important.tzst", files)  # Safe from interruption

# Can be disabled if needed (not recommended)
create_archive("test.tzst", files, use_temp_file=False)

Error Handling

from tzst import TzstArchive
from tzst.exceptions import (
    TzstError,
    TzstArchiveError,
    TzstCompressionError,
    TzstDecompressionError,
    TzstFileNotFoundError
)

try:
    with TzstArchive("archive.tzst", "r") as archive:
        archive.extract()
except TzstDecompressionError:
    print("Failed to decompress archive")
except TzstFileNotFoundError:
    print("Archive file not found")
except KeyboardInterrupt:
    print("Operation interrupted by user")
    # Cleanup handled automatically

Performance and Comparison

Performance Tips

1. Compression levels: Level 3 is optimal for most use cases
2. Streaming: Use for archives larger than 100MB
3. Batch operations: Add multiple files in single session
4. File types: Already compressed files won't compress much further

vs Other Tools

vs tar + gzip:

• Better compression ratios
• Faster decompression
• Modern algorithm

vs tar + xz:

• Significantly faster compression
• Similar compression ratios
• Better speed/compression trade-off

vs zip:

• Better compression
• Preserves Unix permissions and metadata
• Better streaming support

Requirements

• Python 3.12 or higher
• zstandard >= 0.19.0

Development

Setting up Development Environment

This project uses Hatch as the build system:

git clone https://github.com/xixu-me/tzst.git
cd tzst
pip install -e .[dev]

Or with Hatch:

pip install hatch
hatch env create
hatch shell

Running Tests

# Using pytest
pytest --cov=tzst --cov-report=html

# Using Hatch
hatch run pytest --cov=tzst --cov-report=html

Code Quality

# Check code quality
ruff check src tests

# Format code
ruff format src tests

Contributing

We welcome contributions! Please read our Contributing Guide for:

• Development setup and project structure
• Code style guidelines and best practices
• Testing requirements and writing tests
• Pull request process and review workflow

Quick Start for Contributors

git clone https://github.com/xixu-me/tzst.git
cd tzst
pip install -e .[dev]
python -m pytest tests/

Types of Contributions Welcome

• 🐛 Bug fixes - Fix issues in existing functionality
• ✨ Features - Add new capabilities to the library
• 📚 Documentation - Improve or add documentation
• 🧪 Tests - Add or improve test coverage
• ⚡ Performance - Optimize existing code
• 🔒 Security - Address security vulnerabilities

Acknowledgments

• Meta Zstandard for the excellent compression algorithm
• python-zstandard for Python bindings
• The Python community for inspiration and feedback

License

Copyright © 2025 Xi Xu. All rights reserved.

Licensed under the BSD 3-Clause license.