(group) order not preserved

When inserting data into an h5py file object, the order is not preserved. The items (here: groups) are rather ordered alphabetically:

import h5py

with h5py.File("out.h5", "w") as f:
    a = f.create_group("b")
    b = f.create_group("a")


with h5py.File("out.h5", "r") as f:
    print(f.keys())

Output:

<KeysViewHDF5 ['a', 'b']>

Expected output:

<KeysViewHDF5 ['b', 'a']>

I don’t know if this is a property of HDF5, a problem of the reader. or a problem of the writer.

[vasole]

Hi guys, track_order works for me if instead of writing f.keys() I write f[“/”].keys()

[takluyver]

So it does. @aparamon, can you take a look? I can reproduce it with 1.10.4.