Example with Pandas

gistfile1.txt

In [119]: d = {
     ...:     'test1': {
     ...:         0: {'a': {'min': 1, 'mid': 12, 'max': 13},
     ...:             'b': {'min': 2, 'mid': 22, 'max': 23}},
     ...:         3: {'a': {'min': 3, 'mid': 32, 'max': 33},
     ...:             'b': {'min': 4, 'mid': 42, 'max': 43}},
     ...:         8: {'a': {'min': 5, 'mid': 52, 'max': 53},
     ...:             'b': {'min': 6, 'mid': 62, 'max': 63}},
     ...:     },
     ...:     'test2': {
     ...:         0: {'a': {'min': 9, 'mid': 12, 'max': 13},
     ...:             'b': {'min': 8, 'mid': 22, 'max': 23}},
     ...:         3: {'a': {'min': 7, 'mid': 32, 'max': 33},
     ...:             'b': {'min': 6, 'mid': 42, 'max': 43}},
     ...:         8: {'a': {'min': 5, 'mid': 52, 'max': 53},
     ...:             'b': {'min': 4, 'mid': 62, 'max': 63}},
     ...:     },
     ...: }

In [120]: (pd.DataFrame.from_dict(d, orient="index")
     ...:    .stack().apply(pd.Series)
     ...:    .stack().apply(pd.Series)
     ...:    .rename_axis(("Tests", "Id", "Item")))
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-120-8cfba8c10c3d> in <module>()
      2    .stack().apply(pd.Series)
      3    .stack().apply(pd.Series)
----> 4    .rename_axis(("Tests", "Id", "Item")))

/usr/lib/python2.7/site-packages/pandas/core/generic.pyc in rename_axis(self, mapper, axis, copy, inplace)
    618         d = {'copy': copy, 'inplace': inplace}
    619         d[axis] = mapper
--> 620         return self.rename(**d)
    621
    622     #----------------------------------------------------------------------

/usr/lib/python2.7/site-packages/pandas/core/frame.pyc in rename(self, index, columns, **kwargs)
   2522     def rename(self, index=None, columns=None, **kwargs):
   2523         return super(DataFrame, self).rename(index=index, columns=columns,
-> 2524                                              **kwargs)
   2525
   2526     @Appender(_shared_docs['fillna'] % _shared_doc_kwargs)

/usr/lib/python2.7/site-packages/pandas/core/generic.pyc in rename(self, *args, **kwargs)
    587
    588             baxis = self._get_block_manager_axis(axis)
--> 589             result._data = result._data.rename_axis(f, axis=baxis, copy=copy)
    590             result._clear_item_cache()
    591

/usr/lib/python2.7/site-packages/pandas/core/internals.pyc in rename_axis(self, mapper, axis, copy)
   2233         """
   2234         obj = self.copy(deep=copy)
-> 2235         obj.set_axis(axis, _transform_index(self.axes[axis], mapper))
   2236         return obj
   2237

/usr/lib/python2.7/site-packages/pandas/core/internals.pyc in _transform_index(index, func)
   3993     """
   3994     if isinstance(index, MultiIndex):
-> 3995         items = [tuple(func(y) for y in x) for x in index]
   3996         return MultiIndex.from_tuples(items, names=index.names)
   3997     else:

/usr/lib/python2.7/site-packages/pandas/core/internals.pyc in <genexpr>((y,))
   3993     """
   3994     if isinstance(index, MultiIndex):
-> 3995         items = [tuple(func(y) for y in x) for x in index]
   3996         return MultiIndex.from_tuples(items, names=index.names)
   3997     else:

TypeError: 'tuple' object is not callable