[Numpy-discussion] ANN: python-blosc 1.0.4 released

Francesc Alted francesc at continuum.io
Fri Sep 14 09:31:39 EDT 2012

Announcing python-blosc 1.0.4

What is it?

A Python wrapper for the Blosc compression library.

Blosc (http://blosc.pytables.org) is a high performance compressor
optimized for binary data.  It has been designed to transmit data to
the processor cache faster than the traditional, non-compressed,
direct memory fetch approach via a memcpy() OS call.

Blosc works well for compressing numerical arrays that contains data
with relatively low entropy, like sparse data, time series, grids with
regular-spaced values, etc.

python-blosc is a Python package that wraps it.

What is new?

Optimized the amount of data copied during compression (using
_PyBytes_Resize() now instead of previous PyBytes_FromStringAndSize()).

This leads to improvements in compression speed ranging from 1.2x for
highly compressible chunks up to 7x for mostly uncompressible data.
Thanks to Valentin Haenel for this nice contribution.

For more info, you can see the release notes in:


More docs and examples are available in the Quick User's Guide wiki page:


Download sources

Go to:


and download the most recent release from there.

Blosc is distributed using the MIT license, see LICENSES/BLOSC.txt for

Mailing list

There is an official mailing list for Blosc at:

blosc at googlegroups.com

-- Francesc Alted

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