BUG: Series.gt (and other comparison methods) can fail with dtype=object #59418
Open
Description
Pandas version checks
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I have checked that this issue has not already been reported.
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I have confirmed this bug exists on the latest version of pandas.
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I have confirmed this bug exists on the main branch of pandas.
Reproducible Example
>>> import pandas as pd
>>>
>>> x = pd.Series([None], dtype=object)
>>> y = pd.Series([0])
# This raises a: "TypeError: '>' not supported between instances of 'NoneType' and 'int'"
>>> x.gt(y)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/test/venv/lib/python3.12/site-packages/pandas/core/series.py", line 6300, in gt
return self._flex_method(
^^^^^^^^^^^^^^^^^^
File "/home/test/venv/lib/python3.12/site-packages/pandas/core/series.py", line 6246, in _flex_method
return self._binop(other, op, level=level, fill_value=fill_value)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/test/venv/lib/python3.12/site-packages/pandas/core/series.py", line 6195, in _binop
result = func(this_vals, other_vals)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: '>' not supported between instances of 'NoneType' and 'int'
# This runs without error.
>>> x > y
0 False
dtype: bool
# When converted to DataFrames (with object dtypes), .gt runs without error:
>>> x.to_frame().gt(y.to_frame())
0
0 False
# If the series has dtype=float, the comparison runs without error.
>>> x.astype(float).gt(y)
0 False
dtype: boolIssue Description
When a Series has dtype=object, comparison methods (e.g., .gt) can raise a TypeError: '>' not supported error. No error is encountered when using the > operator, or when calling DataFrame.gt, or when the Series has dtype=float.
Expected Behavior
When the Series has dtype=object, the behavior of Series.gt should be consistent with the > operator and with the DataFrame.gt method.
Installed Versions
INSTALLED VERSIONS
------------------
commit : d9cdd2ee5a58015ef6f4d15c7226110c9aab8140
python : 3.12.4.final.0
python-bits : 64
OS : Linux
OS-release : 6.10.2-arch1-1
Version : #1 SMP PREEMPT_DYNAMIC Sat, 27 Jul 2024 16:49:55 +0000
machine : x86_64
processor :
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8
pandas : 2.2.2
numpy : 2.0.1
pytz : 2024.1
dateutil : 2.9.0.post0
setuptools : 71.1.0
pip : 23.2.1
Cython : None
pytest : 8.3.1
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
adbc-driver-postgresql: None
adbc-driver-sqlite : None
bs4 : None
bottleneck : None
dataframe-api-compat : None
fastparquet : None
fsspec : None
gcsfs : None
matplotlib : 3.9.1
numba : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pyreadstat : None
python-calamine : None
pyxlsb : None
s3fs : None
scipy : 1.14.0
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
zstandard : None
tzdata : 2024.1
qtpy : None
pyqt5 : None