nmantani / python-lzrw1-kh

A pure Python implementation of LZRW1/KH compression algorithm

python-lzrw1-kh

This is a pure Python implementation of LZRW1/KH compression algorithm. Python 2 and Python 3 are supported. This implementation is based on the C implementation by Kurt Haenen and the Delphi implementation by Danny Heijl.

This implementation is slow and not suitable for large files.

Installation

pip3 install python-lzrw1-kh

pip3 install https://github.com/nmantani/python-lzrw1-kh/archive/refs/heads/master.zip

Usage

lzrw1_kh.compress() and lzrw1_kh.decompress() take bytes as an argument and return compressed / decompressed bytes.

>>> import lzrw1_kh
>>> lzrw1_kh.compress(b'AAAAAAAABBBBBBBBCCCCCCCC')
b'\x0c\x00@T\x00A\x00\x14B\x00\x14C\x00\x14'
>>> lzrw1_kh.decompress(b'\x0c\x00@T\x00A\x00\x14B\x00\x14C\x00\x14')
b'AAAAAAAABBBBBBBBCCCCCCCC'
>>> 

>>> import hashlib
>>> import lzrw1_kh
>>> data = b"\x90"*1024
>>> hashlib.md5(data).hexdigest()
'e03067ea0b33933f67508ff1f8d0d4d0'
>>> compressed = lzrw1_kh.compress(data)
>>> len(compressed)
9
>>> decompressed = lzrw1_kh.decompress(compressed)
>>> len(decompressed)
1024
>>> hashlib.md5(decompressed).hexdigest()
'e03067ea0b33933f67508ff1f8d0d4d0'
>>> 

Author

Nobutaka Mantani (Twitter: @nmantani)

License

The BSD 2-Clause License (http://opensource.org/licenses/bsd-license.php)