Read HDF5 strings as str with h5py 2.x and 3.0

h5py_strings.py

"""Read HDF5 strings to Python str

h5py 3.0 changed the APIs for storing and reading strings.
This shows how to read strings as Python 3 str if you need
to support both old and new h5py.
"""
import h5py
import numpy as np

f = h5py.File('foo.h5', 'r')
ds = f['data']

if h5py.version.version_tuple[0] == 3:
    strings = ds.asstr()[()]
else:
    # h5py 2.x
    if h5py.check_string_dtype(ds.dtype).encoding == 'utf-8':
        strings = ds[()]
    else:
        # HDF5 ASCII strings
        bytes_data = ds[()]
        strings = np.array([
            b.decode('ascii') for b in bytes_data.flat
        ], dtype=object).reshape(bytes_data.shape)