Not supported for DataFrames Exception triggered by a simple inspect.getmembers() call on a DataFrame

[RichardBruskiewich]

Code Sample, a copy-pastable example if possible

import inspect
import pandas as pd
df = pd.DataFrame()
try:
   members = inspect.getmembers(df)
except Exception as e:
   print(e)

Problem description

A "Not supported for DataFrames Exception" is triggered by a simple inspect.getmembers() call on a DataFrame instance. There are some useful libraries like the Python 'fire' library which are disabled by this bug, which was not present in Pandas Release 0.24.2 but emerged in 0.25.0

Expected Output

A list of DataFrame members (without crashing)

Output of pd.show_versions()

[paste the output of pd.show_versions() here below this line]
INSTALLED VERSIONS

commit : None
python : 3.7.5.final.0
python-bits : 64
OS : Linux
OS-release : 5.3.0-26-generic
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8

pandas : 0.25.1
numpy : 1.18.1
pytz : 2019.3
dateutil : 2.8.1
pip : 20.0.2
setuptools : 45.1.0
Cython : None
pytest : None
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 2.11.1
IPython : None
pandas_datareader: None
bs4 : None
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : None
matplotlib : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pytables : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
xarray : None
xlrd : None
xlwt : None
xlsxwriter : None

[s-scherrer]

This is caused by this in frame.py:

    @property
    def _constructor_expanddim(self):
        raise NotImplementedError("Not supported for DataFrames!")

If we would raise an AttributeError here instead of NotImplementedError then inspect.getmembers should work.

[RichardBruskiewich]

Yes, that would be a solution. It would fix the inspect.getmembers call for sure. I don't know if there are any other exception contexts where this Exception would matter but that's a primary one.

Can you directly fix this or should I issue a pull request on the change?

[s-scherrer]

I guess you can issue a pull request, I'm not a pandas developer either.

[TomAugspurger]

Moving this off 1.0.1, but can likely include it if #31549 is updated in time.

[jorisvandenbossche]

@TomAugspurger there is a 1.0.2 milestone for things that are not urgent enough for / blockers for 1.0.1, but still can be tracked for a bugfix release in general

[TomAugspurger]

Moving off 1.0.2