classification
Title: pandas.to_records can not be saved by numpy.savez
Type: behavior Stage: resolved
Components: Versions: Python 2.7
process
Status: closed Resolution: third party
Dependencies: Superseder:
Assigned To: Nosy List: grampus, steven.daprano
Priority: normal Keywords:

Created on 2018-06-01 06:48 by grampus, last changed 2018-06-01 06:51 by steven.daprano. This issue is now closed.

Messages (2)
msg318364 - (view) Author: Feng (grampus) Date: 2018-06-01 06:48
my first time to report a bug here.
But it is so annoying, I have to report it.
Here is the demonstration of the errors I encounter:

>>> import numpy as np
>>> import pandas as pd
>>> np.__version__
'1.14.3'
>>> pd.__version__
u'0.23.0'

>>> df=pd.DataFrame({'a':range(10)})
>>> df['b']='abc'
>>> df
   a    b
0  0  abc
1  1  abc
2  2  abc
3  3  abc
4  4  abc
5  5  abc
6  6  abc
7  7  abc
8  8  abc
9  9  abc

>>> np.savez_compressed('abc',data=df.to_records(index=False))
>>> a=np.load('abc.npz')
>>> a.keys()
['data']
>>> a['data']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python2.7/site-packages/numpy/lib/npyio.py", line 235, in __getitem__
    pickle_kwargs=self.pickle_kwargs)
  File "/usr/lib64/python2.7/site-packages/numpy/lib/format.py", line 635, in read_array
    shape, fortran_order, dtype = _read_array_header(fp, version)
  File "/usr/lib64/python2.7/site-packages/numpy/lib/format.py", line 523, in _read_array_header
    raise ValueError(msg % (d['descr'],))
ValueError: descr is not a valid dtype descriptor: [(u'a', '<i8'), (u'b', '|O')]
msg318365 - (view) Author: Steven D'Aprano (steven.daprano) * (Python committer) Date: 2018-06-01 06:51
Sorry, this tracker is for the interpreter and standard library. For bugs in third party code like numpy and pandas, you will have to report it on their own bug trackers.
History
Date User Action Args
2018-06-01 06:51:13steven.dapranosetstatus: open -> closed

nosy: + steven.daprano
messages: + msg318365

resolution: third party
stage: resolved
2018-06-01 06:48:48grampuscreate