What’s new in PyTables 0.9.1¶
This release is mainly a maintenance version. In it, some bugs has been fixed and a few improvements has been made. One important thing is that chunk sizes in EArrays has been re-tuned to get much better performance. Besides, it has been tested against the latest Python 2.4 and all unit tests seems to pass fine.
More in detail:
The chunksize computation for EArrays has been re-tuned to allow the compression rations that were usual before 0.9 release.
New –unpackshort and –quantize flags has been added to nctoh5 script. –unpackshort unpack short integer variables to float variables using scale_factor and add_offset netCDF variable attributes. –quantize quantize data to improve compression using least_significant_digit netCDF variable attribute (not active by default). See http://www.esrl.noaa.gov/psd/data/gridded/conventions/cdc_netcdf_standard.shtml for further explanation of what this attribute means. Thanks to Jeff Whitaker for providing this.
Table.itersequence has received a new parameter called “sort”. This allows to disable the sorting of the sequence in case the user wants so.
Now, the AttributeSet class throw an AttributeError on __getattr__ for nonexistent attributes in it. Formerly, the routine returned None, which is pretty much against convention in Python and breaks the built-in hasattr() function. Thanks to Robert Nemec for noting this and offering a patch.
VLArray.read() has changed its behaviour. Now, it always returns a list, as stated in documentation, even when the number of elements to return is 0 or 1. This is much more consistent when representing the actual number of elements on a certain VLArray row.
A Row.getTable() has been added. It is an accessor for the associated Table object.
A File.copyAttrs() has been added. It allows copying attributes from one leaf to other. Properly speaking, this was already there, but not documented :-/
Now, the copy of hierarchies works even when there are scalar Arrays (i.e. Arrays which shape is ()) on it. Thanks to Robert Nemec for providing a patch.
Solved a memory leak regarding the Filters instance associated with the File object, that was not released after closing the file. Now, there are no known leaks on PyTables itself.
Improved security of nodes name checking. Closes #1074335
– Francesc Altet firstname.lastname@example.org