Repr-ing SparseDataFrame after setting a value

[kernc]

Code Sample, a copy-pastable example if possible

>>> sdf = pd.SparseDataFrame(index=[0, 1], columns=[0, 1])
>>> sdf[0][0] = 1  # This warns; ignore
>>> sdf
AttributeError: 'NoneType' object has no attribute 'type'

Problem description

After some value is set on a copy of a SparseSeries, the enclosing SparseDataFrame can no longer be printed (raises AttributeError).

Expected Output

>>> sdf
    0   1
0 NaN NaN
1 NaN NaN

Output of pd.show_versions()

0.19.0+479.git

[jreback]

These are not implemented, so not sure that

In [3]: sdf.loc[0,0] = 1
---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)

this should even work