BUG: mask() and where() do not work pandas.core.arrays.boolean.BooleanDtype

[DriesSchaumont]

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• (optional) I have confirmed this bug exists on the master branch of pandas.

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Note: Please read this guide detailing how to provide the necessary information for us to reproduce your bug.

Code Sample, a copy-pastable example

This does not work:

>>> import pandas as pd
>>> index = pd.MultiIndex.from_arrays([['a', 'a', 'b'], ['c', 'd', 'e']], names=['level1', 'level2'])
>>> test = pd.DataFrame([[1, 2],[3, 4],[5, 6]], index=index, dtype=pd.UInt32Dtype())
>>> column_sums = test.sum(level='level1')
>>> to_remove = column_sums < 100
>>> test.mask(to_remove, inplace=True, level='level1', axis=0, other=pd.NA)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "./site-packages/pandas/core/generic.py", line 9034, in mask
    return self.where(
  File "./site-packages/pandas/core/generic.py", line 9004, in where
    return self._where(
  File "./site-packages/pandas/core/generic.py", line 8854, in _where
    new_data = self._mgr.putmask(
  File "./site-packages/pandas/core/internals/managers.py", line 547, in putmask
    return self.apply(
  File "./site-packages/pandas/core/internals/managers.py", line 406, in apply
    applied = getattr(b, f)(**kwargs)
  File "./site-packages/pandas/core/internals/blocks.py", line 1606, in putmask
    mask = _extract_bool_array(mask)
  File "./site-packages/pandas/core/internals/blocks.py", line 2869, in _extract_bool_array
    assert mask.dtype == bool, mask.dtype
AssertionError: object

This does work:

>>> import pandas as pd
>>> index = pd.MultiIndex.from_arrays([['a', 'a', 'b'], ['c', 'd', 'e']], names=['level1', 'level2'])
>>> test = pd.DataFrame([[1, 2],[3, 4],[5, 6]], index=index, dtype=pd.UInt32Dtype())
>>> column_sums = test.sum(level='level1')
>>> to_remove = (column_sums < 100).astype(bool)
>>> test.mask(to_remove, inplace=True, level='level1', axis=0, other=pd.NA)
>>> test.info()
<class 'pandas.core.frame.DataFrame'>
MultiIndex: 3 entries, ('a', 'c') to ('b', 'e')
Data columns (total 2 columns):
 #   Column  Non-Null Count  Dtype
---  ------  --------------  -----
 0   0       0 non-null      UInt32
 1   1       0 non-null      UInt32
dtypes: UInt32(2)
memory usage: 346.0+ bytes

Problem description

Using mask() or where() with the BooleanDtype as condition raises an AssertionError.

Expected Output

mask() and where() should work with both the bool and the pandas.core.arrays.boolean.BooleanDtype dtype.

Output of pd.show_versions()

INSTALLED VERSIONS

commit : db08276
python : 3.8.5.final.0
python-bits : 64
OS : Linux
OS-release : 5.4.0-42-generic
Version : #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8

pandas : 1.1.3
numpy : 1.19.2
pytz : 2020.1
dateutil : 2.8.1
pip : 20.0.2
setuptools : 44.0.0
Cython : None
pytest : None
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
bs4 : None
bottleneck : None
fsspec : None
fastparquet : None
gcsfs : None
matplotlib : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pytables : None
pyxlsb : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
numba : None

[TomAugspurger]

Thanks for reporting. I think this is a duplicate of #35429 and #36395. Let me know if not.

[DriesSchaumont]

@TomAugspurger I seem to have missed those. Thanks!