Closed
Description
I'm trying to save pd.DataFrame using .to_csv method.
If DataFrame has TimedeltaIndex the error is risen:
>>> dt = pd.Timedelta(seconds=10)
>>> timestamps = [dt, 2*dt, 3*dt]
>>> df = pd.DataFrame({'obs': [11,22,33]}, index=timestamps)
>>> df
obs
00:00:10 11
00:00:20 22
00:00:30 33
>>> df.to_csv('test')
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-27-9b2e5ea53beb> in <module>()
----> 1 df.to_csv('test')
C:\Python34\lib\site-packages\pandas\core\frame.py in to_csv(self, path_or_buf,
sep, na_rep, float_format, columns, header, index, index_label, mode, encoding,
quoting, quotechar, line_terminator, chunksize, tupleize_cols, date_format, doub
lequote, escapechar, decimal, **kwds)
1187 escapechar=escapechar,
1188 decimal=decimal)
-> 1189 formatter.save()
1190
1191 if path_or_buf is None:
C:\Python34\lib\site-packages\pandas\core\format.py in save(self)
1465
1466 else:
-> 1467 self._save()
1468
1469 finally:
C:\Python34\lib\site-packages\pandas\core\format.py in _save(self)
1565 break
1566
-> 1567 self._save_chunk(start_i, end_i)
1568
1569 def _save_chunk(self, start_i, end_i):
C:\Python34\lib\site-packages\pandas\core\format.py in _save_chunk(self, start_i
, end_i)
1592 quoting=self.quoting)
1593
-> 1594 lib.write_csv_rows(self.data, ix, self.nlevels, self.cols, self.
writer)
1595
1596 # from collections import namedtuple
TypeError: Argument 'data_index' has incorrect type (expected numpy.ndarray, got
list)
But if Timedelta is not an Index, but a regular column, everything is OK:
>>> df['timedelta'] = df.index
>>> df.reset_index(drop=True, inplace=True)
>>> df.to_csv('test')
Python 3.4.2 x64 Windows version.
pandas (0.16.2), numpy (1.9.2)