Description
Code Sample, a copy-pastable example if possible
import os
import pandas as pd
s = pd.Series(["a", "b", "c", "a"], dtype="category")
s.astype('category')
FILEPATH = 'example.pickle'
s.to_pickle(FILEPATH)
s = pd.read_pickle(FILEPATH)
os.remove(FILEPATH)
s.astype('category')Output
Traceback (most recent call last):
File "mre.py", line 13, in <module>
s.astype('category')
File "/Users/roy/pandas/pandas/core/generic.py", line 5935, in astype
dtype=dtype, copy=copy, errors=errors, **kwargs
File "/Users/roy/pandas/pandas/core/internals/managers.py", line 581, in astype
return self.apply("astype", dtype=dtype, **kwargs)
File "/Users/roy/pandas/pandas/core/internals/managers.py", line 438, in apply
applied = getattr(b, f)(**kwargs)
File "/Users/roy/pandas/pandas/core/internals/blocks.py", line 555, in astype
return self._astype(dtype, copy=copy, errors=errors, values=values, **kwargs)
File "/Users/roy/pandas/pandas/core/internals/blocks.py", line 606, in _astype
return self.make_block(self.values.astype(dtype, copy=copy))
File "/Users/roy/pandas/pandas/core/arrays/categorical.py", line 524, in astype
self = self.copy() if copy else self
File "/Users/roy/pandas/pandas/core/arrays/categorical.py", line 503, in copy
values=self._codes.copy(), dtype=self.dtype, fastpath=True
File "/Users/roy/pandas/pandas/core/arrays/categorical.py", line 353, in __init__
self._dtype = self._dtype.update_dtype(dtype)
File "/Users/roy/pandas/pandas/core/dtypes/dtypes.py", line 556, in update_dtype
new_ordered_from_sentinel = dtype._ordered_from_sentinel
AttributeError: 'CategoricalDtype' object has no attribute '_ordered_from_sentinel'Problem description
Calling Series.astype('category') on a categorical series loaded using pd.read_pickle errors with pandas 0.25.0rc0. The example code ran without error using pandas 0.24.2
Expected Output
0 a
1 b
2 c
3 a
dtype: category
Output of pd.show_versions()
INSTALLED VERSIONS
commit : c64c9cb
python : 3.7.3.final.0
python-bits : 64
OS : Darwin
OS-release : 18.6.0
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8
pandas : 0.25.0rc0+23.gc64c9cb44
numpy : 1.16.4
pytz : 2019.1
dateutil : 2.8.0
pip : 19.1.1
setuptools : 41.0.1
Cython : 0.29.12
pytest : None
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : None
IPython : None
pandas_datareader: None
bs4 : None
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : None
matplotlib : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pytables : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
xarray : None
xlrd : None
xlwt : None
xlsxwriter : None