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
pd.array([list('test')], dtype='string')
# ValueError: Buffer has wrong number of dimensions (expected 1, got 2)
pd.array([list('test'), list('word')], dtype='string')
# ValueError: Buffer has wrong number of dimensions (expected 1, got 2)
pd.array([list('test'), list('words')], dtype='string')
# <StringArray>
# ["['t', 'e', 's', 't']", "['w', 'o', 'r', 'd', 's']"]
# Length: 2, dtype: string
pd.array([list('test')])
# <NumpyExtensionArray>
# [['t', 'e', 's', 't']]
# Length: 1, dtype: objectIssue Description
I'm trying to transform a list of list of strings into a StringArray, but the pd.array method with dtype='string' doesn't work when the second last level list contains lists of same length, raising an exception (see example). If the lists have different lengths, then the output doesn't raise an error and is correct.
In an older version of pandas (1.5.3), it produced a list of same length, but containing repeated casts of string arrays
<StringArray>
[
["['t' 'e' 's' 't']", "['t' 'e' 's' 't']", "['t' 'e' 's' 't']",
"['t' 'e' 's' 't']"]
]
Shape: (1, 4), dtype: string
Expected Behavior
Same as pd.array([list('test')]) but with StringArray type.
Installed Versions
INSTALLED VERSIONS
commit : d9cdd2e
python : 3.12.3.final.0
python-bits : 64
OS : Windows
OS-release : 11
Version : 10.0.22631
machine : AMD64
processor : Intel64 Family 6 Model 154 Stepping 3, GenuineIntel
byteorder : little
LC_ALL : None
LANG : en
LOCALE : English_Europe.1252
pandas : 2.2.2
numpy : 1.26.4
pytz : 2024.1
dateutil : 2.9.0.post0
setuptools : 75.1.0
pip : 24.2
Cython : None
pytest : 7.4.4
hypothesis : None
sphinx : 7.3.7
blosc : None
feather : None
xlsxwriter : None
lxml.etree : 5.2.1
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 3.1.4
IPython : 8.27.0
pandas_datareader : None
adbc-driver-postgresql: None
adbc-driver-sqlite : None
bs4 : 4.12.3
bottleneck : 1.3.7
dataframe-api-compat : None
fastparquet : None
fsspec : 2024.6.1
gcsfs : None
matplotlib : 3.9.2
numba : 0.60.0
numexpr : 2.8.7
odfpy : None
openpyxl : 3.1.5
pandas_gbq : None
pyarrow : 16.1.0
pyreadstat : None
python-calamine : None
pyxlsb : None
s3fs : 2024.6.1
scipy : 1.13.1
sqlalchemy : 2.0.34
tables : 3.10.1
tabulate : 0.9.0
xarray : 2023.6.0
xlrd : None
zstandard : 0.23.0
tzdata : 2023.3
qtpy : 2.4.1
pyqt5 : None