BUG: DateOffset pickle bug when months=12 #34511
Description
-
[ x] I have checked that this issue has not already been reported.
-
[ x] I have confirmed this bug exists on the latest version of pandas.
-
(optional) I have confirmed this bug exists on the master branch of pandas.
Note: Please read this guide detailing how to provide the necessary information for us to reproduce your bug.
Code Sample, a copy-pastable example
import pickle import pandas as pd offset = pd.DateOffset(months=12) pickle.dump(offset, open("/tmp/o.p", "wb")) loaded = pickle.load(open("/tmp/o.p", "rb")) print(loaded) # <DateOffset: months=12, years=1> Problem description
If you pickle a pandas DateOffset instance with months=12, and then unpickle it, you have a DateOffset(months=12, years=1) instance (effectively a 2 year date offset object.
Arguably one shouldn't create a 12 month date offset in preference to a 1 year offset, but this is still bad behaviour imho.
Expected Output
print(loaded)
<DateOffset: months=12>
Output of pd.show_versions()
INSTALLED VERSIONS
commit : None
python : 3.8.3.final.0
python-bits : 64
OS : Darwin
OS-release : 18.7.0
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : en_GB.UTF-8
LOCALE : en_GB.UTF-8
pandas : 1.0.3
numpy : 1.18.1
pytz : 2020.1
dateutil : 2.8.1
pip : 20.0.2
setuptools : 46.4.0.post20200518
Cython : None
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
pytest : None
pyxlsb : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
xlsxwriter : None
numba : None