Series.is_unique has errors on objects with __ne__ defined #20661
Description
Code Sample, a copy-pastable example if possible
In [2]: import pandas as pd ...: ...: class Foo(object): ...: def __init__(self, val): ...: self._value = val ...: ...: def __ne__(self, other): ...: raise Exception("NEQ not supported") ...: In [3]: li = [Foo(i) for i in range(5)] In [4]: s = pd.Series(li, index=[i for i in range(5)]) In [5]: s.is_unique Exception ignored in: 'util._checknan' Traceback (most recent call last): File "<ipython-input-2-91ad489145cd>", line 8, in __ne__ Exception: NEQ not supported Exception ignored in: 'util._checknan' Traceback (most recent call last): File "<ipython-input-2-91ad489145cd>", line 8, in __ne__ Exception: NEQ not supported Exception ignored in: 'util._checknan' Traceback (most recent call last): File "<ipython-input-2-91ad489145cd>", line 8, in __ne__ Exception: NEQ not supported Exception ignored in: 'util._checknan' Traceback (most recent call last): File "<ipython-input-2-91ad489145cd>", line 8, in __ne__ Exception: NEQ not supported Exception ignored in: 'util._checknan' Traceback (most recent call last): File "<ipython-input-2-91ad489145cd>", line 8, in __ne__ Exception: NEQ not supported Out[5]: TrueProblem description
I'm working with a third party library that has a class that, for good reasons, raises an Exception when the method __ne__ is called. I want to put that class into a pandas Series. Eventually, I hope to do this with the new ExtensionArray feature. Anyhow, I uncovered an issue in my debugger (pydev) which was throwing an exception when I looked into the corresponding Series.
So if you have an object that defines __ne__, then is_unique will fail (as shown above). I can't figure out where util._checknan is being called, but I think it is deep in the cython area.
I think this will need to work correctly if I want to use ExtensionArray to hold these kinds of objects.
Expected Output
Out[5]: True Output of pd.show_versions()
INSTALLED VERSIONS
commit: 402ad45
python: 3.6.4.final.0
python-bits: 64
OS: Windows
OS-release: 10
machine: AMD64
processor: Intel64 Family 6 Model 60 Stepping 3, GenuineIntel
byteorder: little
LC_ALL: None
LANG: None
LOCALE: None.None
pandas: 0.23.0.dev0+683.g402ad45da.dirty
pytest: 3.4.0
pip: 9.0.1
setuptools: 38.5.1
Cython: 0.25.1
numpy: 1.14.1
scipy: 1.0.0
pyarrow: 0.8.0
xarray: None
IPython: 6.2.1
sphinx: 1.7.1
patsy: 0.5.0
dateutil: 2.6.1
pytz: 2018.3
blosc: 1.5.1
bottleneck: 1.2.1
tables: 3.4.2
numexpr: 2.6.4
feather: None
matplotlib: 2.2.0
openpyxl: 2.5.0
xlrd: 1.1.0
xlwt: 1.3.0
xlsxwriter: 1.0.2
lxml: 4.1.1
bs4: 4.6.0
html5lib: 1.0.1
sqlalchemy: 1.2.5
pymysql: 0.8.0
psycopg2: None
jinja2: 2.10
s3fs: 0.1.3
fastparquet: None
pandas_gbq: None
pandas_datareader: None