How to compute and display compression ratios of HDF5 datasets in an HDF5 file using Python

h5comprat.py

import sys
import h5py


def comp_ratio(name, obj):
    if isinstance(obj, h5py.Dataset) and obj.chunks is not None:
        if obj.id.get_create_plist().get_nfilters():
            stor_size = obj.id.get_storage_size()
            if stor_size != 0:
                ratio = float(obj.nbytes) / float(stor_size)
                print(f'Compression ratio for "{obj.name}": {ratio}')


if len(sys.argv) > 1:
    with h5py.File(sys.argv[1], mode='r') as h5f:
        print(f'Compression ratios for datasets in HDF5 file: {h5f.filename}')
        h5f.visititems(comp_ratio)
else:
    print('Usage: h5comprat.py <HDF5 file path>')
    raise SystemExit('No HDF5 file path given')