DEPR: deprecate Index.is_object
- [ ] progress towards https://github.com/pandas-dev/pandas/issues/50042
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

@topper-123 Do you know what I got wrong? I have looked at some other pull requests, but they have both common and different files to fix. Actually, I am not sure how to detect which file I should change is_object to is_object_dtype. Do you have any suggestion for me? Hi @bang128 I think you're getting quite close. The issues that I see are:

1: doc/source/whatsnew/v2.0.0.rst
There are some artifacts in `doc/source/whatsnew/v2.0.0.rst` likely from a git rebase. Can you fix those.

2: failures
In general you need to go through the test logs above (click the "details" button) to see which errors have been raised. I can see these, which need to be fixed in one test log:

```
FAILED pandas/tests/series/methods/test_describe.py::TestSeriesDescribe::test_numeric_result_dtype[complex] - TypeError: a must be an array of real numbers
FAILED pandas/tests/series/methods/test_describe.py::TestSeriesDescribe::test_numeric_result_dtype[complex64] - TypeError: a must be an array of real numbers
FAILED pandas/tests/series/methods/test_describe.py::TestSeriesDescribe::test_numeric_result_dtype[complex128] - TypeError: a must be an array of real numbers
```

Looks like something related to the treatment of complex numbers. I'm not able to run these tests right now, but if you could attempt to solve them, I can take a closer look tonight and help you fix them, if you haven't been able to before.

There may be others, I haven't checked all test failures. Hi @bang128  can you try to fix the issues in `doc/source/whatsnew/v2.0.0.rst` and push again. I think that may be enough to fix this.

Regarding how to find the instances to correct, you should run the pandas test suite locally and fix errors that show up. Depending on your coding proficiency, this may not be entirely trivial, but it'll be a good learning exercise in any case :-)   Okay, let me try to fix the doc issue first

 This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. Hi @bang128. What's the status on your PR?

It look good to me, but needs a rebase. 

 Can you rebase. Ping. Should I rebase for you? Hey @bang128 , the rebase was a bit difficult, so I’ve rebased & merged this. Thanks a lot for yoyr contribution!