BrandonFors/pandas-github-issues huggingface dataset:
feature #58141: Consistent naming conventions for string dtype aliases
State: open

Key implementation steps:
- Created factory functions (string, datetime, integer, floating, decimal, boolean, list, categorical, interval, period, sparse, date, duration, map, struct) to generate pandas dtypes (e.g., StringDtype, Int64Dtype, ArrowDtype) based on parameters like backend, bits, unit, and precision.
- Added support for Pandas, NumPy and PyArrow backends, enabling seamless switching (e.g., integer() returns Int64Dtype for Pandas or ArrowDtype(pa.int64()) for PyArrow).
- Implemented parameter validation to ensure correct usage (e.g., validating mode in string() to be "string" or "binary", and unit in datetime() for NumPy).
- Integrated PyArrow types for advanced dtypes (e.g., pa.float64(), pa.list_(), pa.map_()), supporting modern data processing frameworks.
- Implemented comprehensive tests in test_factory.py to validate dtype creation across all functions, ensuring correct behavior for different backends, verifying string representations (e.g., "double[pyarrow]" for pa.float64()), and confirming proper error handling (e.g., raising ValueError for invalid inputs).
- Addressed PyArrow compatibility by implementing correct method calls, such as using pa.bool_() for boolean dtypes, ensuring proper integration.

This change simplifies dtype creation, reduces duplication, and ensures compatibility across backends, making it easier to extend support for new dtypes in the future.

- [x] closes #58141 
- [x] [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
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] 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/v3.0.0.rst` file if fixing a bug or adding a new feature.


Labels:
name: Enhancement
name: API Design
name: Stale

Comments:
@simonjayhawkins Hi! Just wanted to check if this PR needs anything else from my side. Thanks in advance for reviewing
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.
feature #49580: support new-style float_format string in to_csv
State: closed

feat(to_csv): support new-style float_format strings using str.format

Detect and process new-style format strings (e.g., "{:,.2f}") in the float_format parameter of to_csv.

- Check if float_format is a string and matches new-style pattern
- Convert it to a callable (e.g., lambda x: float_format.format(x))
- Ensure compatibility with NaN values and mixed data types
- Improves formatting output for floats when exporting to CSV

Example:
df = pd.DataFrame([1234.56789, 9876.54321])
df.to_csv(float_format="{:,.2f}")  # now outputs formatted values like 1,234.57 and support new-style without .format

- [x] closes #49580
- [x] [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
- [x] 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.
- [x] Added an entry in the latest `doc/source/whatsnew/v3.0.0.rst` file if fixing a bug or adding a new feature.


Labels:
name: Enhancement
name: IO CSV
description: read_csv, to_csv

Comments:
@simonjayhawkins Hi! Just wanted to check if this PR needs anything else from my side. Thanks in advance for reviewing
Could you add a whatsnew entry in `v3.0.0.rst`?
@mroeschke What do you think of the updates?
I failed 1 test, but I don't know why because it doesn't seem to be related to the changes
Thanks @pedromfdiogo
TST: update xfail xarray version check in to_xarray test
State: closed

Started to see xpass in https://github.com/pandas-dev/pandas/pull/61594, so updating the version check here. Not sure this is entirely covered by CI, but tested this locally with a few different xarray versions.

Labels:
name: Testing
description: pandas testing functions or related to the test suite

Comments:
Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
git checkout 2.3.x
git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
git cherry-pick -x -m1 7def76a79361c8f6aa2893d9a559da03c6cb6d3a
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
git commit -am 'Backport PR #61648: TST: update xfail xarray version check in to_xarray test'
```

4. Push to a named branch:

```
git push YOURFORK 2.3.x:auto-backport-of-pr-61648-on-2.3.x
```

5. Create a PR against branch 2.3.x, I would have named this PR:

> "Backport PR #61648 on branch 2.3.x (TST: update xfail xarray version check in to_xarray test)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the `Still Needs Manual Backport` label once the PR gets merged.

If these instructions are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                
Backport -> https://github.com/pandas-dev/pandas/pull/61652
WEB: Moving maintainers to inactive (no answer from them)
State: closed

I couldn't get an answer from @jreback @topper-123 @alimcmaster1 regarding being active or unactive for some time.

I'll leave this open for few days, in case they see it an can confirm. But in the past we've been moving people to inactive if they didn't seem active for a long time and we couldn't get confirmation from them on whether they want to continue to be active or not.

Labels:
name: Web
description: pandas website

Comments:
well i do follow things and in particular not too happy about what is going on

will reserve the right to vote if needed
Thanks Jeff for confirming, great news that you are still following the project and interested in voting if needed. Very happy to revert the changes and leaving you as active.

And if you want to share the feedback on why you aren't happy on what's going on, I'm surely very interested to know your opinion.
I didn't hear from Terji, so I guess he could be moved to inactive, but I think I prefer to just close this PR, since I'm not sure what the governance says in this case.
> I didn't hear from Terji, so I guess he could be moved to inactive, but I think I prefer to just close this PR, since I'm not sure what the governance says in this case.

@datapythonista discussed this at the steering committee meeting. The core team decides its membership, so it really should be a core team decision on how to manage the non-response of any individual.
fix std/var with complex array
State: closed

- [x] closes #61645
- [x] [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
- [x] 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.
- [x] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.


Labels:
name: Reduction Operations
description: sum, mean, min, max, etc.

Comments:
These failures seem unrelated, is the CI broken?
Thanks @randolf-scholz
BUG: Add PyArrow datelike type support for `map()`
State: open

- [x] closes #61231 (Replace xxxx with the GitHub issue number)
- [x] [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
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] 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.


Labels:
name: Bug
name: Apply
description: Apply, Aggregate, Transform, Map
name: Arrow
description: pyarrow functionality

Comments:
Can you add tests based on the original issue
Looks like some tests are failing in the CI.  Can you address those?
@jbrockmendel sorry I was inactive last 2 weeks. Will take a look at this issue atm
I now used `self.dtype.kind in "mM"` instead. 

I saw that the test function (`test_map()`) uses it to test out datetime likes. So I realized its best to use it to filter out datetime likes on the function as well
@jbrockmendel Is the fix for the existing test_map enough? or should I add a test similar to the issue as well? Thanks!
Can you add a test associated with the original issue.  it isn't clear from the edited test that it is fixed
BUG: Fix GroupBy aggregate coersion of outputs inconsistency for pyarrow dtypes
State: open

- [x] closes #61636
- [x] [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
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/whatsnew/v3.0.0.rst` file if fixing a bug or adding a new feature.

## Description
Fix a bug in `DataFrameGroupBy.agg` when applied to columns with `ArrowDtype`, where pandas attempted to cast the result back to the original dtype.

## Cause
1. `ExtensionArray._from_scalars()` should raise only `ValueError` or `TypeError`, instead of `pa.ArrowNotImplementedError`.
2. `ArrowExtensionArray._from_sequence()` may attempt an invalid cast, and if it succeeds, it can unintentionally alter the actual data type.

Labels:
name: Bug
name: Groupby
name: Stale
name: Arrow
description: pyarrow functionality

Comments:
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.
Fix void dtype handling
State: open

- [x] closes #54810
- [x] [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).
- [x] 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.


Labels:
name: Bug
name: Constructors
description: Series/DataFrame/Index/pd.array Constructors
name: Stale

Comments:
which `doc/source/whatsnew/vX.X.X.rst` am I supposed to edit?
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.
Description of pandas_datetime_exec function.
State: closed

Added the function description documentation for `pandas_datetime_exec` in the following location.

https://github.com/pandas-dev/pandas/blob/main/pandas/_libs/src/datetime/pd_datetime.c

- [x] closes #61631 (Replace xxxx with the GitHub issue number)
- [ ] [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.


Labels:
name: Docs

Comments:
@mroeschke Can you please review this change whenever you get a chance?
Thanks @kunaljani1100 
Thanks you very much @mroeschke for taking a look into this.
DOC: Title Capitalization and Grammar Fix
State: closed

Currrently the title of the repository in the README.md reads the following text: pandas: powerful Python data analysis toolkit

Since the title is grammatically incorrect and also has incorrect capitalization, this pull request was opened to ensure that the title is capitalized properly and there are no grammatical errors in the title.

Labels:
name: Docs

Comments:
Sure, thanks @kunaljani1100
BUG: to_stata erroring when encoded text and normal text have mismatched length
State: closed

- [x] closes #61583  (Replace xxxx with the GitHub issue number)
- [x] [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
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

I removed the encoded check in stata.py and replaced it with a normal check, if the encoded check was there for any particular reason I can standardize them the other way

Labels:
name: Bug
name: IO Stata
description: read_stata, to_stata

Comments:
Thanks @eicchen
BUG: Fix infer_dtype result for float with embedded pd.NA
State: closed

- [x] closes #61621
- [x] [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
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/whatsnew/v3.0.0.rst` file if fixing a bug or adding a new feature.

## Description
Fix a bug in :func:`api.types.infer_dtype` returning "mixed-integer-float" for float and ``pd.NA`` mix.

## Cause
This problem occurred because the existing `is_float_array` internally fixed `skipna=False`. It was solved by adding the `skipna` argument.


Labels:
name: Bug
name: Missing-data
description: np.nan, pd.NaT, pd.NA, dropna, isnull, interpolate
name: Dtype Conversions
description: Unexpected or buggy dtype conversions

Comments:
Is there anything else I can do about this? I would appreciate it if you could review it when you have time.
Thanks @heoh!
@rhshadrach I could really use this fix. As this is not much of a breaking change, can't we change the milestone to 2.3.2?
I would highly appreciate it. <3
BUG: DataFrame.explode fails with str dtype
State: closed

- [ ] closes #xxxx (Replace xxxx with the GitHub issue number)
- [ ] [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.

This operation works on all other dtypes, e.g.

```python
df = pd.DataFrame({"a": [1, 2]})
print(df.explode(column="a"))
#    a
# 0  1
# 1  2
```


Labels:
name: Bug
name: Reshaping
description: Concat, Merge/Join, Stack/Unstack, Explode
name: Strings
description: String extension data type and string data

Comments:
@datapythonista 

> Btw, did we have problems before to have the `result is not df` assert? I haven't used it before, it'd be good to understand in which tests it make sense. Thanks!

I think it makes sense to check this when we have a no-op that should return a copy. If the operation modifies the data (which is the case for the vast majority of tests), I don't think it needs to be checked.
@datapythonista - fixed up the docs build, this should be ready.
Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
git checkout 2.3.x
git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
git cherry-pick -x -m1 73db25d585a12e587beffef83449dbdd5d16d0f6
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
git commit -am 'Backport PR #61623: BUG: DataFrame.explode fails with str dtype'
```

4. Push to a named branch:

```
git push YOURFORK 2.3.x:auto-backport-of-pr-61623-on-2.3.x
```

5. Create a PR against branch 2.3.x, I would have named this PR:

> "Backport PR #61623 on branch 2.3.x (BUG: DataFrame.explode fails with str dtype)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the `Still Needs Manual Backport` label once the PR gets merged.

If these instructions are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                
Backport -> https://github.com/pandas-dev/pandas/pull/61699
DOC: Clarify that 'names' is only used when constructing a MultiIndex
State: closed

- [x] closes #19082
- [ ] [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  
      **(Not applicable — this is a documentation-only change)**
- [x] 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  
      **(Not applicable — no new functions or arguments were added)**
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature  
      **(Optional — this change may be too minor, but can be added under "Documentation" if desired)**

### Description

Clarifies in the `Index` class docstring that the `names` parameter is only relevant when constructing a `MultiIndex`. This prevents confusion where users expect `names=('a',)` to behave like `name='a'` for regular Index objects.

No changes were made to the behavior of `Index`, only to the documentation for better clarity.


Labels:

Comments:
I'll close this PR as it doesn't feel useful. Feel free to comment if I'm missing something, and I can surely reopen.
BUG: Fix RecursionError when apply native container types as a func
State: closed

- [x] closes #61565
- [x] [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
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
  - Nothing new added.
- [x] Added an entry in the latest `doc/source/whatsnew/v3.0.0.rst` file if fixing a bug or adding a new feature.

## Description
Fixes a bug in `DataFrame.apply` raising `RecursionError` when passing `func=list[int]`.

## Cause
The existing code handled parameterized container types, but not native container types, yielding false positives. I also added a check for `types.GenericAlias` to handle native container types.

#### Reference: https://github.com/python/cpython/blob/3.12/Lib/typing.py#L1251
> ```py
> class _GenericAlias(_BaseGenericAlias, _root=True):
>     ...
>     # Objects which are instances of this class include:
>     # * Parameterized container types, e.g. `Tuple[int]`, `List[int]`.
>     #  * Note that native container types, e.g. `tuple`, `list`, use
>     #    `types.GenericAlias` instead.
> ```

Labels:
name: Dtype Conversions
description: Unexpected or buggy dtype conversions

Comments:
Thanks @heoh
feat(1.5.x): Add support for python 3.12
State: closed

- [ ] closes #xxxx (Replace xxxx with the GitHub issue number)
- [ ] [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.


Labels:

Comments:
I don't think we have plans to release any new 1.5 version, or provide support of any version older than 2.3. It would also be useful to reference an issue or provide a description, so we have context on your proposal.
Thanks for the PR, but as mentioned the community no longer plans to supporting pandas 1.5 anymore, so further support needs to be accomplished in forks of pandas. Closing as no action.