can't print embedded ndarray
Just playing with pandas.  I was using structured array.  I tried converting my structured array to pandas.  It was OK, until I tried with a field that was itself a (variable length) ndarray.

arr = np.empty ((len(results),), dtype=[(... various fields ommitted,

```
                ('err', object),
                                    ('bursts', int),
                ('per', float), ...
                ])
```

Next the array is filled with data.
The field 'err' is then filled in with a ndarray (vector) whose size is variable per instance.

Now convert to df:

from pandas import *
df = DataFrame (arr)

Any attempt to print anything with 'err' field gives an exception

/home/nbecker/hn-8psk/<ipython-input-81-68bace0c3dbe> in <module>()
----> 1 df['err']

/usr/lib/python2.7/site-packages/IPython/core/displayhook.pyc in **call**(self, result)
    300             self.start_displayhook()
    301             self.write_output_prompt()
--> 302             format_dict = self.compute_format_data(result)
    303             self.write_format_data(format_dict)
    304             self.update_user_ns(result)

/usr/lib/python2.7/site-packages/IPython/core/displayhook.pyc in compute_format_data(self, result)
    213             MIME type representation of the object.
    214         """
--> 215         return self.shell.display_formatter.format(result)
    216 
    217     def write_format_data(self, format_dict):

/usr/lib/python2.7/site-packages/IPython/core/formatters.pyc in format(self, obj, include, exclude)
    120                     continue
    121             try:
--> 122                 data = formatter(obj)
    123             except:
    124                 # FIXME: log the exception

/usr/lib/python2.7/site-packages/IPython/core/formatters.pyc in **call**(self, obj)
    441                 type_pprinters=self.type_printers,
    442                 deferred_pprinters=self.deferred_printers)
--> 443             printer.pretty(obj)
    444             printer.flush()
    445             return stream.getvalue()

/usr/lib/python2.7/site-packages/IPython/lib/pretty.pyc in pretty(self, obj)
    349             if hasattr(obj_class, '_repr_pretty_'):
    350                 return obj_class._repr_pretty_(obj, self, cycle)
--> 351             return _default_pprint(obj, self, cycle)
    352         finally:
    353             self.end_group()

/usr/lib/python2.7/site-packages/IPython/lib/pretty.pyc in _default_pprint(obj, p, cycle)
    467     if getattr(klass, '__repr__', None) not in _baseclass_reprs:
    468         # A user-provided repr.

--> 469         p.text(repr(obj))
    470         return
    471     p.begin_group(1, '<')

/usr/lib64/python2.7/site-packages/pandas/core/series.pyc in **repr**(self)
    435             result = self._get_repr(print_header=True,
    436                                     length=len(self) > 50,
--> 437                                     name=True)
    438         else:
    439             result = '%s' % ndarray.__repr__(self)

/usr/lib64/python2.7/site-packages/pandas/core/series.pyc in _get_repr(self, name, print_header, length, na_rep, float_format)
    494             return '%s    %s' % (str(k).ljust(padSpace), v)
    495 
--> 496         it = [_format(idx, v) for idx, v in izip(string_index, vals)]
    497 
    498         if print_header and have_header:

/usr/lib64/python2.7/site-packages/pandas/core/series.pyc in _format(k, v)
    488 
    489         def _format(k, v):
--> 490             if isnull(v):
    491                 v = na_rep
    492             if isinstance(v, (float, np.floating)):

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

In [82]: 
