Closed
Description
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I have checked that this issue has not already been reported.
-
I have confirmed this bug exists on the latest version of pandas.
-
I have confirmed this bug exists on the master branch of pandas.
Reproducible Example
import os
os.environ["PANDAS_DATA_MANAGER"] = "array"
import pandas as pd, numpy as np
df = pd.DataFrame(index=np.arange(10))
df["foo"] = np.ones((10, 1))
# ValueError: Expected a 1D array, got an array with shape (10, 1)
<details>
<summary> Full traceback </summary>
```pytb
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
/usr/local/lib/python3.9/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
3360 try:
-> 3361 return self._engine.get_loc(casted_key)
3362 except KeyError as err:
/usr/local/lib/python3.9/site-packages/pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()
/usr/local/lib/python3.9/site-packages/pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()
pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
pandas/_libs/hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
KeyError: 'foo'
The above exception was the direct cause of the following exception:
KeyError Traceback (most recent call last)
/usr/local/lib/python3.9/site-packages/pandas/core/frame.py in _set_item_mgr(self, key, value)
3750 try:
-> 3751 loc = self._info_axis.get_loc(key)
3752 except KeyError:
/usr/local/lib/python3.9/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
3362 except KeyError as err:
-> 3363 raise KeyError(key) from err
3364
KeyError: 'foo'
During handling of the above exception, another exception occurred:
ValueError Traceback (most recent call last)
/var/folders/bd/43q20k0n6z15tdfzxvd22r7c0000gn/T/ipykernel_14506/151211532.py in <module>
5
6 df = pd.DataFrame(index=np.arange(10))
----> 7 df["foo"] = np.ones((10, 1))
/usr/local/lib/python3.9/site-packages/pandas/core/frame.py in __setitem__(self, key, value)
3610 else:
3611 # set column
-> 3612 self._set_item(key, value)
3613
3614 def _setitem_slice(self, key: slice, value):
/usr/local/lib/python3.9/site-packages/pandas/core/frame.py in _set_item(self, key, value)
3795 value = np.tile(value, (len(existing_piece.columns), 1)).T
3796
-> 3797 self._set_item_mgr(key, value)
3798
3799 def _set_value(
/usr/local/lib/python3.9/site-packages/pandas/core/frame.py in _set_item_mgr(self, key, value)
3752 except KeyError:
3753 # This item wasn't present, just insert at end
-> 3754 self._mgr.insert(len(self._info_axis), key, value)
3755 else:
3756 self._iset_item_mgr(loc, value)
/usr/local/lib/python3.9/site-packages/pandas/core/internals/array_manager.py in insert(self, loc, item, value)
872 value = value[0, :] # type: ignore[index]
873 else:
--> 874 raise ValueError(
875 f"Expected a 1D array, got an array with shape {value.shape}"
876 )
ValueError: Expected a 1D array, got an array with shape (10, 1)Issue Description
Using the array manager, a 2d array with only one non-singleton dimension causes errors when assigned to a dataframe.
This does not happen with the BlockManager. I would assume the same thing would work, since these should be pretty equivalent.
Expected Behavior
This works fine:
The behavior with the block manager is expected.
import os
os.environ["PANDAS_DATA_MANAGER"] = "block"
import pandas as pd, numpy as np
df = pd.DataFrame(index=np.arange(10))
df["foo"] = np.ones((10, 1))Installed Versions
INSTALLED VERSIONS
------------------
commit : 945c9ed766a61c7d2c0a7cbb251b6edebf9cb7d5
python : 3.9.9.final.0
python-bits : 64
OS : Darwin
OS-release : 20.6.0
Version : Darwin Kernel Version 20.6.0: Tue Oct 12 18:33:42 PDT 2021; root:xnu-7195.141.8~1/RELEASE_X86_64
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : None
LOCALE : None.UTF-8
pandas : 1.3.4
numpy : 1.20.3
pytz : 2021.3
dateutil : 2.8.2
pip : 21.3.1
setuptools : 59.0.1
Cython : None
pytest : 6.2.5
hypothesis : None
sphinx : 4.1.2
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 3.0.3
IPython : 7.29.0
pandas_datareader: None
bs4 : None
bottleneck : None
fsspec : 2021.11.1
fastparquet : None
gcsfs : None
matplotlib : 3.5.0
numexpr : 2.7.3
odfpy : None
openpyxl : 3.0.9
pandas_gbq : None
pyarrow : None
pyxlsb : None
s3fs : None
scipy : 1.7.3
sqlalchemy : None
tables : 3.6.1
tabulate : None
xarray : 0.20.1
xlrd : 1.2.0
xlwt : None
numba : 0.54.1