pylzss - LZSS Compression Library

0.3.8 · active · verified Thu Apr 16

pylzss is a Python library designed for decoding and encoding data compressed with the LZSS algorithm. It provides efficient handling of LZSS-compressed streams, often found in embedded systems or older file formats. The current version is 0.3.8, with recent releases focusing on bug fixes, build system improvements, and wider platform support.

Common errors

```
ModuleNotFoundError: No module named 'pylzss'
```
cause The pylzss library is not installed in your current Python environment.

fix Install the library using pip: `pip install pylzss`
```
SystemError: PY_SSIZE_T_CLEAN should be defined for functions that use 's#' formats
```
cause You are using an older version of pylzss (prior to 0.3.1) with Python 3.10 or a newer Python version, which introduced breaking changes for C extensions.

fix Upgrade pylzss to version 0.3.1 or higher: `pip install --upgrade pylzss`
```
ERROR: Could not find a version that satisfies the requirement pylzss==0.3.5
```
cause Version 0.3.5 of pylzss was removed from PyPI due to severe issues, making it unavailable for installation.

fix Install a newer, stable version of pylzss, such as 0.3.6 or later: `pip install pylzss>=0.3.6`

Warnings

breaking Version 0.3.5 was pulled from PyPI due to critical issues. Attempting to install or use it will lead to unexpected behavior or installation failures.
Fix: Always use `pylzss` version 0.3.6 or newer. If you have 0.3.5 installed, upgrade immediately with `pip install --upgrade pylzss`.
breaking Version 0.3.3 was incorrectly versioned and never properly released to PyPI. It should be avoided as it may cause installation problems or contain critical bugs.
Fix: Do not attempt to use or install `pylzss==0.3.3`. Use `pylzss==0.3.4` or any newer version.
gotcha Versions of `pylzss` older than 0.3.1 can raise a `SystemError` when used with Python 3.10 or newer due to API changes in Python's C extension handling.
Fix: Ensure you are using `pylzss` version 0.3.1 or newer. Upgrade with `pip install --upgrade pylzss` if you are on an older version and Python 3.10+.

Install

pip install pylzss Install pylzss

Imports

LzssDecoder
```
from pylzss import LzssDecoder
```
LzssEncoder
```
from pylzss import LzssEncoder
```

Quickstart

This quickstart demonstrates how to use `pylzss` to compress and decompress a byte string. It initializes an `LzssEncoder` to compress the `original_data` and then uses an `LzssDecoder` to reconstruct it, verifying that the decoded data matches the original.

from pylzss import LzssEncoder, LzssDecoder

# Example data
original_data = b"A Python library for decoding/encoding LZSS-compressed data. " * 5

# Encode the data
encoder = LzssEncoder()
encoded_data = encoder.encode(original_data)

print(f"Original size: {len(original_data)} bytes")
print(f"Encoded size: {len(encoded_data)} bytes")

# Decode the data
decoder = LzssDecoder()
decoded_data = decoder.decode(encoded_data)

print(f"Decoded size: {len(decoding_data)} bytes")
assert original_data == decoded_data
print("Encoding and decoding successful!")

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