What's new in h5py 3.2
======================

New features
------------

* Added support to use the HDF5 ROS3 driver to access HDF5 files on S3
  (:pr:`1755`). This is not enabled in the pre-built packages on PyPI. To use
  it, ensure HDF5 is built with read-only S3 support enabled, and then
  :ref:`build h5py from source <source_install>` using that HDF5 library.

Breaking changes & deprecations
-------------------------------

* Python 3.7 is now the minimum supported version. It may still be possible to
  use this release with Python 3.6, but it isn't tested and wheels are not
  provided for Python 3.6.
* Setting the config option ``default_file_mode`` to values other than ``'r'``
  is deprecated. Pass the desired mode when opening a :class:`~.File` instead.

Exposing HDF5 functions
-----------------------

* ``H5Pset_fapl_ros3`` & ``H5Pget_fapl_ros3`` (where HDF5 is built with
  read-only S3 support).

Bug fixes
---------

* :exc:`OSError` exceptions raised by h5py should now have a useful ``.errno``
  attribute, where HDF5 provides this information. Subclasses such as
  :exc:`FileNotFoundError` should also be raised where appropriate (:pr:`1815`).
* Fix reading data with a datatype of variable-length arrays of fixed length
  strings (:issue:`1817`).
* Fix :meth:`.Dataset.read_direct` and :meth:`.Dataset.write_direct` when the
  source and destination have different shapes (:pr:`1796`).
* Fix selecting data using integer indices in :meth:`.Dataset.read_direct`
  and :meth:`.Dataset.write_direct` (:pr:`1818`).
* Fix exception handling in :meth:`.Group.visititems` (:issue:`1740`).
* Issue a warning when ``File(..., swmr=True)`` is specified with any mode other
  than ``'r'``, as the SWMR option is ignored in these cases (:pr:`1812`).
* Fix NumPy 1.20 deprecation warnings concerning the use of None as shape, and
  the deprecated aliases np.float, np.int and np.bool (:pr:`1780`).

3.2.1 bug fix release
---------------------

* Fix :attr:`.File.driver` when the read-only S3 driver is available (:pr:`1844`).