Missing entries in low-level API docs

[takluyver]

Including at least:

• h5py.h5d functions
• h5py.h5i functions
• h5py.h5z functions
• h5py.h5d.PropDAID

From #1620 (comment)

[takluyver]

It looks like where we use

.. automodule:: h5py.h5i
    :members:

to document all functions in a module, it only includes functions which are declared in the relevant .pxd file. We either need to list the functions explicitly in the doc source (like we do for h5f and a number of other modules), or make sure they're in the .pxd file (like we do for h5pl).

[aragilar]

Does :nodoc-members: help? I'm surprised that the .pxd file is used, I would have thought that would only be for the build, and not for runtime, or is something implicitly set on objects defined within the .pxd which is then reflected by them being found by sphinx?

[takluyver]

h5d.open has a docstring, so it can't just be that.

I can never remember which bits of Sphinx use runtime introspection and which parse source code. I'm surprised that the pxd file matters as well, but it seems like it does!

[takluyver]

Weirdly, today the functions are there. Either one of our recent PRs fixed it (#1624?), or it's an intermittent fault, or I was just somehow rather blind yesterday.

I'm going to reorganise the h5d page to better match other similar pages, with 'Functional API' at the top.

[takluyver]

Done in #1637.