MNT: fix up from mds changes

[tacaswell]

• Deal with new header documents
• deal with docs being read-only

[ericdill]

For my own knowledge, when would node.attrs[key] = value fail?

[ericdill]

Looks good. Thanks for doing this

[tacaswell]

Most of h5py works by casting things to numpy and then mapping from numpy -> hdf5's type system. Anything that fails along that path can't be shove in without custom serialization logic. The simplest is a dict:

In [7]: import h5py

In [8]: f = h5py.File(':memory:')

In [9]: f.attrs
Out[9]: <Attributes of HDF5 object at 140225191548680>

In [10]: f.attrs['foo'] = {'a': 1}
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-10-2a6fb928d0e9> in <module>()
----> 1 f.attrs['foo'] = {'a': 1}

h5py/_objects.pyx in h5py._objects.with_phil.wrapper (-------src-dir-------/h5py/_objects.c:2458)()

h5py/_objects.pyx in h5py._objects.with_phil.wrapper (-------src-dir-------/h5py/_objects.c:2415)()

/home/tcaswell/.virtualenvs/dd_py3k/lib/python3.4/site-packages/h5py/_hl/attrs.py in __setitem__(self, name, value)
     85         use the methods create() and modify().
     86         """
---> 87         self.create(name, data=value, dtype=base.guess_dtype(value))
     88 
     89     @with_phil

/home/tcaswell/.virtualenvs/dd_py3k/lib/python3.4/site-packages/h5py/_hl/attrs.py in create(self, name, data, shape, dtype)
    161             # Make HDF5 datatype and dataspace for the H5A calls
    162             if use_htype is None:
--> 163                 htype = h5t.py_create(original_dtype, logical=True)
    164                 htype2 = h5t.py_create(original_dtype)  # Must be bit-for-bit representation rather than logical
    165             else:

h5py/h5t.pyx in h5py.h5t.py_create (-------src-dir-------/h5py/h5t.c:15483)()

h5py/h5t.pyx in h5py.h5t.py_create (-------src-dir-------/h5py/h5t.c:15314)()

h5py/h5t.pyx in h5py.h5t.py_create (-------src-dir-------/h5py/h5t.c:15232)()

TypeError: Object dtype dtype('O') has no native HDF5 equivalent

but custom objects and unicode strings also fail.

[tacaswell]

I also view this as a MVP, others are more than welcome to write dialects that output the data formatted how ever they want.

[ericdill]

Ah cool, thanks for the clear example