pd.testing.assert_index_equal fails with check_exact=False

[vhully]

pd.testing.assert_index_equal fails with pint dtype with check_exact=False. It works with the default check_exact=True.

Code:

import pandas as pd
import pint_pandas

index_1 = index_2 = pd.Index(pd.Series([10, 20], dtype="pint[s]"), name="x")
pd.testing.assert_index_equal(index_1, index_2, check_exact=False)

Error:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[38], [line 5](vscode-notebook-cell:?execution_count=38&line=5)
      [2](vscode-notebook-cell:?execution_count=38&line=2) import pint_pandas
      [4](vscode-notebook-cell:?execution_count=38&line=4) index_1 = index_2 = pd.Index(pd.Series([10, 20], dtype="pint[s]"), name="x")
----> [5](vscode-notebook-cell:?execution_count=38&line=5) pd.testing.assert_index_equal(index_1, index_2, check_exact=False)

    [... skipping hidden 1 frame]

File testing.pyx:55, in pandas._libs.testing.assert_almost_equal()

File testing.pyx:160, in pandas._libs.testing.assert_almost_equal()

File testing.pyx:145, in pandas._libs.testing.assert_almost_equal()

File ~/draft/hdf/__venv__/lib/python3.12/site-packages/pint/facets/numpy/quantity.py:217, in NumpyQuantity.__len__(self)
    [216](https://file+.vscode-resource.vscode-cdn.net/home/vianney/draft/hdf/~/draft/hdf/__venv__/lib/python3.12/site-packages/pint/facets/numpy/quantity.py:216) def __len__(self) -> int:
--> [217](https://file+.vscode-resource.vscode-cdn.net/home/vianney/draft/hdf/~/draft/hdf/__venv__/lib/python3.12/site-packages/pint/facets/numpy/quantity.py:217)     return len(self._magnitude)

TypeError: object of type 'numpy.int64' has no len()

[andrewgsavage]

yea this is a pain and means pint-pandas skips the pandas tests that use it.

I'm assuming this is the same issue as this pandas-dev/pandas#48919
it'll need fixing in pandas.