YearOffset issue

[cibic89]

Code Sample, a copy-pastable example if possible

import pandas as pd
import_date_end = pd.to_datetime("2019-01-01")
import_date_end - pd.offsets.YearOffset(n=8, normalize=True, month=1)

Problem description

It's because the YearOffset month is Jan and so is the given month

---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
<ipython-input-50-1062b3c9831a> in <module>
      1 import_date_end# - pd.offsets.YearOffset(n=8, normalize=True, month=1)
----> 2 pd.to_datetime("2019-01-01") - pd.offsets.YearOffset(n=8, normalize=True, month=1)

pandas/_libs/tslibs/offsets.pyx in pandas._libs.tslibs.offsets.BaseOffset.__rsub__()

pandas/_libs/tslibs/offsets.pyx in pandas._libs.tslibs.offsets._BaseOffset.__add__()

~\miniconda3\envs\test\lib\site-packages\pandas\tseries\offsets.py in wrapper(self, other)
    110                 other = other.tz_localize(None)
    111 
--> 112             result = func(self, other)
    113 
    114             if self._adjust_dst:

~\miniconda3\envs\test\lib\site-packages\pandas\tseries\offsets.py in apply(self, other)
   1950     @apply_wraps
   1951     def apply(self, other):
-> 1952         years = roll_yearday(other, self.n, self.month, self._day_opt)
   1953         months = years * 12 + (self.month - other.month)
   1954         return shift_month(other, months, self._day_opt)

pandas/_libs/tslibs/offsets.pyx in pandas._libs.tslibs.offsets.roll_yearday()

pandas/_libs/tslibs/offsets.pyx in pandas._libs.tslibs.offsets.get_day_of_month()

NotImplementedError: 

Expected Output

Timestamp('2012-01-01 00:00:00')

Output of pd.show_versions()

INSTALLED VERSIONS

commit : None
python : 3.7.5.final.0
python-bits : 64
OS : Windows
OS-release : 10
machine : AMD64
processor : Intel64 Family 6 Model 79 Stepping 1, GenuineIntel
byteorder : little
LC_ALL : None
LANG : None
LOCALE : None.None

pandas : 0.25.3
numpy : 1.17.3
pytz : 2019.3
dateutil : 2.8.1
pip : 19.3.1
setuptools : 41.6.0.post20191030
Cython : None
pytest : None
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : 1.2.6
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 2.10.3
IPython : 7.9.0
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 : 1.2.0
xlwt : None
xlsxwriter : 1.2.6

[mroeschke]

As the error states, this offset is not implemented.

Additionally in #7706, looks like we intend to eventually make this offset private, so I don't believe this offset is intended to work.

In the meantime, you can try to use DateOffset instead: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.tseries.offsets.DateOffset.html