Pandas: reindexing / "'Index' object has no attribute 'freq'"

[Will Furnass]

I've created a DataFrame using read_clipboard() (Pandas built from Git trunk) and am having problems reindexing unless I select rows using the [:] notation.  IIRC the index was defined using 'set_index("Timestamp")'. 

In [47]:

q_and_turb_df

df

Out[47]:

<class 'pandas.core.frame.DataFrame'>
Index: 61507 entries, 2010-01-31 15:30:00 to 2011-11-03 09:15:00
Data columns:
Q      61507  non-null values
NTU    61507  non-null values
dtypes: float64(2)

In [50]:

q_and_turb_df[:50000000]['Q'] < 14

df[:50000000]['Q'] < 14

Out[50]:

time
2010-01-31 15:30:00     True
2010-01-31 15:45:00     True
2010-01-31 16:00:00     True
2010-01-31 16:15:00    False
2010-01-31 16:30:00    False

<<snip; all fine here>>

In [51]:

q_and_turb_df['Q'] < 14

df['Q'] < 14

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
/home/will/Dropbox/PhD/AI_general/Semblance/<ipython-input-51-2f53055c9488> in <module>()
----> 1 q_and_turb_df['Q'] < 14

/usr/lib/python2.7/dist-packages/IPython/core/displayhook.pyc in __call__(self, result)
    236             self.start_displayhook()
    237             self.write_output_prompt()
--> 238             format_dict = self.compute_format_data(result)
    239             self.write_format_data(format_dict)
    240             self.update_user_ns(result)

/usr/lib/python2.7/dist-packages/IPython/core/displayhook.pyc in compute_format_data(self, result)
    148             MIME type representation of the object.
    149         """
--> 150         return self.shell.display_formatter.format(result)
    151 
    152     def write_format_data(self, format_dict):

/usr/lib/python2.7/dist-packages/IPython/core/formatters.pyc in format(self, obj, include, exclude)
    124                     continue
    125             try:
--> 126                 data = formatter(obj)
    127             except:
    128                 # FIXME: log the exception


/usr/lib/python2.7/dist-packages/IPython/core/formatters.pyc in __call__(self, obj)
    445                 type_pprinters=self.type_printers,
    446                 deferred_pprinters=self.deferred_printers)
--> 447             printer.pretty(obj)
    448             printer.flush()
    449             return stream.getvalue()

/usr/lib/python2.7/dist-packages/IPython/lib/pretty.pyc in pretty(self, obj)
    352                 if callable(obj_class._repr_pretty_):
    353                     return obj_class._repr_pretty_(obj, self, cycle)
--> 354             return _default_pprint(obj, self, cycle)
    355         finally:
    356             self.end_group()

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

--> 474         p.text(repr(obj))
    475         return
    476     p.begin_group(1, '<')

/usr/local/lib/python2.7/dist-packages/pandas-0.8.0.dev_1ea766c-py2.7-linux-x86_64.egg/pandas/core/series.pyc in __repr__(self)
    710                     else fmt.print_config.max_rows)
    711         if len(self.index) > max_rows:
--> 712             result = self._tidy_repr(min(30, max_rows - 4))
    713         elif len(self.index) > 0:
    714             result = self._get_repr(print_header=True,

/usr/local/lib/python2.7/dist-packages/pandas-0.8.0.dev_1ea766c-py2.7-linux-x86_64.egg/pandas/core/series.pyc in _tidy_repr(self, max_vals)
    728                                                   name=False)
    729         result = head + '\n...\n' + tail
--> 730         return '%s\n%s' % (result, self._repr_footer())
    731 
    732     def _repr_footer(self):

/usr/local/lib/python2.7/dist-packages/pandas-0.8.0.dev_1ea766c-py2.7-linux-x86_64.egg/pandas/core/series.pyc in _repr_footer(self)
   2551 
   2552     def _repr_footer(self):
-> 2553         if self.index.freq is not None:
   2554             freqstr = 'Freq: %s, ' % self.index.freqstr
   2555         else:

AttributeError: 'Index' object has no attribute 'freq'

Any thoughts?

Cheers,

Will 

[Chang She]

It looks like somehow your index is all datetime but is not a DatetimeIndex (which has the .freq property). I made a pandas github issue here: https://github.com/pydata/pandas/issues/1187. It should be an easy fix.

That being said, it actually looks like that DataFrame.set_index should do the right thing here. Would you mind putting more information on how to reproduce the error on the github issue linked to above?

Thanks,

Chang