Pandas version checks
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[X] I have confirmed this bug exists on the main branch of pandas.
Reproducible Example
import pandas as pd
x = pd.Index(['a', 'b', 'a'], dtype=object)
print(f"{x.min() = }") # This works
y = pd.Index(['a', 'b', 'a'], dtype="string[python]")
print(f"{y.min() = }") # This works
z = pd.Index(['a', 'b', 'a'], dtype="string[pyarrow]")
print(f"{z.min() = }") # This errors
Issue Description
When an Index with string[pyarrow] data contains repeated data, for example pd.Index(['a', 'b', 'a'], dtype="string[pyarrow]"), .min() / .max() fail.
The above code snippet fails with
Traceback (most recent call last):
File "/Users/james/projects/dask/dask/string-min.py", line 11, in <module>
print(f"{z.min() = }")
File "/Users/james/mambaforge/envs/dask-py39/lib/python3.9/site-packages/pandas/core/indexes/base.py", line 7225, in min
return self._values.min(skipna=skipna) # type: ignore[attr-defined]
AttributeError: 'ArrowStringArray' object has no attribute 'min'
Expected Behavior
I'd expect using string[pyarrow] data to return the same result as object and string[python].
cc @phofl @mroeschke
Installed Versions
INSTALLED VERSIONS
------------------
commit : 8dab54d6573f7186ff0c3b6364d5e4dd635ff3e7
python : 3.9.15.final.0
python-bits : 64
OS : Darwin
OS-release : 22.2.0
Version : Darwin Kernel Version 22.2.0: Fri Nov 11 02:08:47 PST 2022; root:xnu-8792.61.2~4/RELEASE_X86_64
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8
pandas : 1.5.2
numpy : 1.24.0
pytz : 2022.6
dateutil : 2.8.2
setuptools : 59.8.0
pip : 22.3.1
Cython : None
pytest : 7.2.0
hypothesis : None
sphinx : 4.5.0
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : 1.1
pymysql : None
psycopg2 : None
jinja2 : 3.1.2
IPython : 8.7.0
pandas_datareader: None
bs4 : 4.11.1
bottleneck : None
brotli :
fastparquet : 2023.1.0
fsspec : 2022.11.0
gcsfs : None
matplotlib : 3.6.2
numba : None
numexpr : 2.8.3
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : 10.0.1
pyreadstat : None
pyxlsb : None
s3fs : 2022.11.0
scipy : 1.9.3
snappy :
sqlalchemy : 1.4.46
tables : 3.7.0
tabulate : None
xarray : 2022.9.0
xlrd : None
xlwt : None
zstandard : None
tzdata : None
Comment From: jrbourbeau
Hmm, actually this may be more generic than when there's repeated data. I just stumbled across this case where there aren't any repeated items in the index
In [1]: import pandas as pd
In [2]: x = pd.Index(['k', 'l', 'i'], dtype='string[python]')
In [3]: x.min()
Out[3]: 'i'
In [4]: x = pd.Index(['k', 'l', 'i'], dtype='string[pyarrow]')
In [5]: x.min()
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
Cell In[5], line 1
----> 1 x.min()
File ~/mambaforge/envs/dask-py39/lib/python3.9/site-packages/pandas/core/indexes/base.py:7225, in Index.min(self, axis, skipna, *args, **kwargs)
7221 return self._na_value
7223 if not self._is_multi and not isinstance(self._values, np.ndarray):
7224 # "ExtensionArray" has no attribute "min"
-> 7225 return self._values.min(skipna=skipna) # type: ignore[attr-defined]
7227 return super().min(skipna=skipna)
AttributeError: 'ArrowStringArray' object has no attribute 'min'
Comment From: phofl
Hi, thx for your report. Yep this is a generic problem.
If you have this in a Series, then we are accessing reduction functions through _reduce while the index class calls them directly, which raises the error.