What’s new in h5py 3.6

New features

  • Pre-built packages are now available for Python 3.10.


  • Using Dataset.astype() as a context manager (with dset.astype(t):) is deprecated. Slice the object returned by astype instead (data = dset.astype(t)[:10]). This works from h5py 3.0 onwards.

  • Getting the value of h5py.get_config().default_file_mode now issues a deprecation warning. This has been 'r' by default from h5py 3.0, and cannot be changed since 3.3.

Building h5py

  • h5py now requires the oldest-supported-numpy package at build time, instead of maintaining its own list of the oldest supported NumPy versions. The effect should be similar, but hopefully more reliable.


  • The custom setup.py test has been removed. tox should be used instead during development (see Run the tests), and pytest --pyargs h5py can be used to test h5py after installation.