Release notes for PyTables 3.0 series¶
Changes from 2.4 to 3.0¶
Basic support for HDF5 drivers. Now it is possible to open/create an HDF5 file using one of the SEC2, DIRECT, LOG, WINDOWS, STDIO or CORE drivers. Users can also set the main driver parameters (closes gh-166). Thanks to Michal Slonina.
Basic support for in-memory image files. An HDF5 file can be set from or copied into a memory buffer (thanks to Michal Slonina). This feature is only available if PyTables is built against HDF5 1.8.9 or newer. Closes gh-165 and gh-173.
File.get_filesize()method for retrieving the HDF5 file size.
Implemented methods to get/set the user block size in a HDF5 file (closes gh-123)
All read methods now have an optional out argument that allows to pass a pre-allocated array to store data (closes gh-192)
Added support for the floating point data types with extended precision (Float96, Float128, Complex192 and Complex256). This feature is only available if numpy provides it as well. Closes gh-51 and gh-214. Many thanks to Andrea Bedini.
create_xxx()signatures. Now it is possible to create all data sets
Tablefrom existing Python objects (closes gh-61 and gh-249). See also the API changes section.
Complete rewrite of the
nodes.filenodemodule. Now it is fully compliant with the interfaces defined in the standard
iomodule. Only non-buffered binary I/O is supported currently. See also the API changes section. Closes gh-244.
New pt2to3 tool is provided to help users to port their applications to the new API (see API changes section).
Improved runtime checks on dynamic loading of libraries: meaningful error messages are generated in case of failure. Also, now PyTables no more alters the system PATH. Closes gh-178 and gh-179 (thanks to Christoph Gohlke).
Improved list of search paths for libraries as suggested by Nicholaus Halecky (see gh-219).
The internal Blosc library has been upgraded to version 1.2.3.
Packaging: since this release the standard tar-ball package no more includes the PDF version of the “PyTables User Guide”, so it is a little bit smaller now. The complete and pre-build version of the documentation both in HTML and PDF format is available on the file download area on SourceForge.net. Closes: gh-172.
PyTables now requires Python 2.6 or newer.
Minimum supported version of Numexpr is now 2.0.
This means that many methods, attributes, module global variables and also
keyword parameters have been renamed to be compliant with PEP8 style
guidelines (e.g. the
tables.hdf5Version constant has been renamed into
We made the best effort to maintain compatibility to the old API for existing applications. In most cases, the old 2.x API is still available and usable even if it is now deprecated (see the Deprecations section).
The only important backwards incompatible API changes are for names of function/methods arguments. All uses of keyword arguments should be checked and fixed to use the new naming convention.
The new pt2to3 tool can be used to port PyTables based applications to the new API.
Many deprecated features and support for obsolete modules has been dropped:
is_promodule constant has been removed
The nra module and support for the obsolete numarray module has been removed. The numarray flavor is no more supported as well (closes gh-107).
Support for the obsolete Numeric module has been removed. The numeric flavor is no longer available (closes gh-108).
The tables.netcdf3 module has been removed (closes gh-68).
exceptions.Incompat16Warningexception has been removed
File.create_external_link()method no longer has a keyword parameter named warn16incompat. It was deprecated in PyTables 2.4.
File.create_table()methods of the
Fileobjects gained a new (optional) keyword argument named
obj. It can be used to initialize the newly created dataset with an existing Python object, though normally these are numpy arrays.
The atom/descriptor and shape parameters are now optional if the obj argument is provided.
nodes.filenodehas been completely rewritten to be fully compliant with the interfaces defined in the
The FileNode classes currently implemented are intended for binary I/O.
the FileNode base class is no more available,
the lineSeparator property is no more available and the
\ncharacter is always used as line separator.
The __version__ module constants has been removed from almost all the modules (it was not used after the switch to Git). Of course the package level constant (
tables.__version__) still remains. Closes gh-112.
lrange()has been dropped in favor of xrange (gh-181)
Please refer to the Migrating from PyTables 2.x to 3.x document for more details about API changes and for some useful hint about the migration process from the 2.X API to the new one.
Other possibly incompatible changes¶
All methods of the
Tableclass that take start, stop and step parameters (including
Table.iterrows(), etc) have been redesigned to have a consistent behaviour. The meaning of the start, stop and step and their default values now always work exactly like in the standard
sliceobjects. Closes gh-44 and gh-255.
Unicode attributes are not stored in the HDF5 file as pickled string. They are now saved on the HDF5 file as UTF-8 encoded strings.
Although this does not introduce any API breakage, files produced are different (for unicode attributes) from the ones produced by earlier versions of PyTables.
System attributes are now stored in the HDF5 file using the character set that reflects the native string behaviour: ASCII for Python 2 and UTF8 for Python 3. In any case, system attributes are represented as Python string.
Tableas well as the
Table.itersorted()now behave like functions in the standard
itertoolsmodule. If the start parameter is provided and stop is None then the array/table is iterated from start to the last line. In PyTables < 3.0 only one element was returned.
The use of upper-case keyword arguments in the
open_file()function and the
Fileclass initializer is now deprecated. All parameters defined in the
tables/parameters.pymodule can still be passed as keyword argument to the
open_file()function just using a lower-case version of the parameter name.
Better check access on closed files (closes gh-62)
File.renameNode()where in certain cases
File._g_updateLocation()was wrongly called (closes gh-208). Thanks to Michka Popoff.
Fixed ptdump failure on data with nested columns (closes gh-213). Thanks to Alexander Ford.
tables.tests.test_nestedtypes.ColsTestCase.test_00a_reprtest method. Now the
reprof of cols on big-endian platforms is correctly handled (closes gh-237).
—The PyTables Developers