import fund # my package
fd = fund.Fund.load('210004')
df = fd.data[:5]   # read 5 rows for testing

# pandas reported error
# get the same error using store = pd.io.pytables.HDFStore('store.h5'), store[]=...
folder = '/Users/william/'
df.to_hdf(folder + 'cpi.h5', 'cpi')

# rewrite it literally
# I got ignorable warning (PerformanceWarning) but no error
folder = '/Users/william/'
matrix =[[1.331, 2.061, 0.0053, 'ssss', 'ssss', None],
[1.324, 2.054, 0.0015, 'ssss', 'ssss', None],
[1.322, 2.052, 0.0015, 'ssss', 'ssss', None],
[1.32, 2.05, 0.0138, 'ssss', 'ssss', None],
[1.302, 2.032, 0.011699999999999999, 'ssss', 'ssss', None]]
df2=pd.DataFrame(matrix,columns=df.keys(),index=df.index)
df2.to_hdf(folder + 'cpi.h5', 'cpi')

2017-07-24  True    True    True    True    True    False
2017-07-21  True    True    True    True    True    False
2017-07-20  True    True    True    True    True    False
2017-07-19  True    True    True    True    True    False
2017-07-18  True    True    True    True    True    False

RecursionErrorTraceback (most recent call last) <ipython-input-135-2186e340ee8f> in <module>()
      5 store = pd.io.pytables.HDFStore('store.h5')
      6 folder = '/Users/william/'
----> 7 df.to_hdf(folder + 'cpi.h5', 'cpi')
      8
      9 store = pd.io.pytables.HDFStore('store.h5')

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/core/generic.py in to_hdf(self, path_or_buf, key, **kwargs)    1297     1298         from pandas.io import pytables
-> 1299         return pytables.to_hdf(path_or_buf, key, self, **kwargs)    1300     1301     def to_msgpack(self, path_or_buf=None, encoding='utf-8', **kwargs):

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/pytables.py in to_hdf(path_or_buf, key, value, mode, complevel, complib, append,
**kwargs)
    278         with HDFStore(path_or_buf, mode=mode, complevel=complevel,
    279                       complib=complib) as store:
--> 280             f(store)
    281     else:
    282         f(path_or_buf)

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/pytables.py in <lambda>(store)
    272         f = lambda store: store.append(key, value, **kwargs)
    273     else:
--> 274         f = lambda store: store.put(key, value, **kwargs)
    275
    276     path_or_buf = _stringify_path(path_or_buf)

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/pytables.py in put(self, key, value, format, append, **kwargs)
    889             format = get_option("io.hdf.default_format") or 'fixed'
    890         kwargs = self._validate_format(format, kwargs)
--> 891         self._write_to_group(key, value, append=append, **kwargs)
    892
    893     def remove(self, key, where=None, start=None, stop=None):

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/pytables.py in _write_to_group(self, key, value, format, index, append, complib, encoding, **kwargs)    1331     1332         # write the object
-> 1333         s.write(obj=value, append=append, complib=complib, **kwargs)    1334     1335         if s.is_table and index:

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/pytables.py in write(self, obj, **kwargs)    2911             # I have no idea why, but writing values before items fixed #2299    2912             blk_items = data.items.take(blk.mgr_locs)
-> 2913             self.write_array('block%d_values' % i, blk.values, items=blk_items)    2914             self.write_index('block%d_items' % i, blk_items)    2915

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/pandas/io/pytables.py in write_array(self, key, value, items)    2679             vlarr = self._handle.create_vlarray(self.group, key,    2680
_tables().ObjectAtom())
-> 2681             vlarr.append(value)    2682         else:    2683             if empty_array:

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/tables/vlarray.py in append(self, sequence)
    517         atom = self.atom
    518         if not hasattr(atom, 'size'):  # it is a pseudo-atom
--> 519             sequence = atom.toarray(sequence)
    520             statom = atom.base
    521         else:

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/tables/atom.py in toarray(self, object_)    1084     1085     def toarray(self, object_):
-> 1086         buffer_ = self._tobuffer(object_)    1087         array = numpy.ndarray(buffer=buffer_, dtype=self.base.dtype,    1088   shape=len(buffer_))

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/tables/atom.py in _tobuffer(self, object_)    1218     1219     def _tobuffer(self, object_):
-> 1220         return six.moves.cPickle.dumps(object_, six.moves.cPickle.HIGHEST_PROTOCOL)    1221     1222     def fromarray(self, array):

RecursionError: maximum recursion depth exceeded