# Release notes for PyTables 3.5 series

Author

  PyTables Developers

Contact

  pytables-dev@googlegroups.com

## Changes from 3.5.1 to 3.5.2

- Fixed compatibility with python 3.8: Fixed Dictionary keys changed during iteration RuntimeError while moving/renaming a node. Thanks to Christoph Gohlke for reporting and Miro Hrončok for help with building PyTables for python 3.8alpha (cython compatibility). see gh-733 and PR #737.

- Fixed a bug in offset calculations producing floats instead of ints affecting python 3. See PR #736. Thanks to Brad Montgomery.

## Changes from 3.5.0 to 3.5.1

- Maintenance release to fix how PyPi repo is handling wheel versions.

## Changes from 3.4.4 to 3.5.0

### Improvements

> - When copying data from native HDF5 files with padding in compound types, the padding is not removed now by default. This allows for better compatibility with existing HDF5 applications that expect the padding to stay there. Also, when the description is a NumPy struct array with padding, this is honored now. The previous behaviour (i.e. getting rid of paddings) can be replicated by passing the new allow_padding parameter when opening a file. For some examples, see the new examples/tables-with-padding.py and examples/attrs-with-padding.py. For details on the implementation see gh-720.

> - Added a new flag –dont-allow-padding in ptrepack utility so as to replicate the previous behaviour of removing padding during file copies. The default is to honor the original padding in copies.

> - Improve compatibility with numpy 1.16.

> - Improve detection of the LZO2 library at build time.

> - Suppress several warnings.

> - Add AVX2 support for Windows. See PR #716. Thanks to Robert McLeod.