List view

BUG: <code>DataFrame[StringDtype].where(DataFrame[bool], list[str])</code> returns object type instead of StringDtype.

Bug

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#63842 In pandas-dev/pandas;

· mroeschke opened on Jan 24, 2026

BUG: string regex operation with unicode escape sequence failing

Arrowpyarrow functionalitypyarrow functionality

RegressionFunctionality that used to work in a prior pandas versionFunctionality that used to work in a prior pandas version

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#63901 In pandas-dev/pandas;

· jorisvandenbossche opened on Jan 27, 2026

API/BUG: support for operations with custom objects / object dtype

Status: Open.

#64107 In pandas-dev/pandas;

· jorisvandenbossche opened on Feb 10, 2026

BUG: Different result from str.find depending on dtype

Arrowpyarrow functionalitypyarrow functionality

Bug

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#64123 In pandas-dev/pandas;

· brsr opened on Feb 12, 2026

BUG: to_hdf on dataframe with string column failing with compression

Bug

IO HDF5read_hdf, HDFStoreread_hdf, HDFStore

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#64180 In pandas-dev/pandas;

· jorisvandenbossche opened on Feb 17, 2026

BUG: normalize_json no longer supports top-level missing entries

Bug

IO JSONread_json, to_json, json_normalizeread_json, to_json, json_normalize

Needs TriageIssue that has not been reviewed by a pandas team memberIssue that has not been reviewed by a pandas team member

Status: Open.

#64188 In pandas-dev/pandas;

· fedefusco29 opened on Feb 17, 2026

BUG: StringArray __array_ufunc__ validation of result should not require strings

Bug

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#40800 In pandas-dev/pandas;

· johnflavin opened on Apr 6, 2021

REGR: Index.astype(&lt;numpy string dtype&gt;) started failing

Astype

BytesDtype

IndexRelated to the Index class or subclassesRelated to the Index class or subclasses

RegressionFunctionality that used to work in a prior pandas versionFunctionality that used to work in a prior pandas version

Status: Open.

#50127 In pandas-dev/pandas;

· jorisvandenbossche opened on Dec 8, 2022

API: with CoW, should every new Series/DataFrame object also have its own new Index objects?

API Design

Copy / view semantics

IndexRelated to the Index class or subclassesRelated to the Index class or subclasses

Status: Open.

#53721 In pandas-dev/pandas;

· jorisvandenbossche opened on Jun 19, 2023

BUG: <code>df1.merge(df2, on='ds', how='outer')</code> not convert column <code>ds</code> to the highest resolution datetime type of the two dfs

Bug

Non-Nanodatetime64/timedelta64 with non-nanosecond resolutiondatetime64/timedelta64 with non-nanosecond resolution

ReshapingConcat, Merge/Join, Stack/Unstack, ExplodeConcat, Merge/Join, Stack/Unstack, Explode

Status: Open.

#55212 In pandas-dev/pandas;

· seanslma opened on Sep 20, 2023

REGR: groupby.transform with a UDF performance

Closing CandidateMay be closeable, needs more eyeballsMay be closeable, needs more eyeballs

Copy / view semantics

Groupby

PerformanceMemory or execution speed performanceMemory or execution speed performance

RegressionFunctionality that used to work in a prior pandas versionFunctionality that used to work in a prior pandas version

Transformationse.g. cumsum, diff, ranke.g. cumsum, diff, rank

Status: Open.

#55256 In pandas-dev/pandas;

· rhshadrach opened on Sep 23, 2023

PERF: <code>DataFrame.copy(deep=True)</code> returns a view on the original pyarrow buffer

Copy / view semantics

Needs DiscussionRequires discussion from core team before further actionRequires discussion from core team before further action

PerformanceMemory or execution speed performanceMemory or execution speed performance

Status: Open.

#61930 In pandas-dev/pandas;

· TomAugspurger opened on Jul 23, 2025

API: reconsider returning read-only arrays from DataFrame/Series .array/.values/__array__

API Design

Copy / view semantics

Needs DiscussionRequires discussion from core team before further actionRequires discussion from core team before further action

Status: Open.

#63099 In pandas-dev/pandas;

· jorisvandenbossche opened on Nov 12, 2025

BUG: <code>.dt.seconds</code> Discrepancy Between NumPy and PyArrow Timedelta Dtypes

Arrowpyarrow functionalitypyarrow functionality

Bug

Needs DiscussionRequires discussion from core team before further actionRequires discussion from core team before further action

TimedeltaTimedelta data typeTimedelta data type

Status: Open.

#63283 In pandas-dev/pandas;

· mattharrison opened on Dec 6, 2025

BUG(pandas 3.0 regression): <code>drop(index=...)</code> doesn't accept NA values when using arrow dtype in index

Arrowpyarrow functionalitypyarrow functionality

Bug

Missing-datanp.nan, pd.NaT, pd.NA, dropna, isnull, interpolatenp.nan, pd.NaT, pd.NA, dropna, isnull, interpolate

RegressionFunctionality that used to work in a prior pandas versionFunctionality that used to work in a prior pandas version

Status: Open.

#63304 In pandas-dev/pandas;

· tswast opened on Dec 8, 2025

BUG: Division results in 0 values for large dfs with numpy==2.3.5

Bug

Upstream issueIssue related to pandas dependencyIssue related to pandas dependency

Status: Open.

#63320 In pandas-dev/pandas;

· tilyevsky12 opened on Dec 10, 2025

BUG: (pandas 3.0rc0) <code>str.cat</code> is not retaining <code>index</code> dtype

Bug

IndexRelated to the Index class or subclassesRelated to the Index class or subclasses

Needs DiscussionRequires discussion from core team before further actionRequires discussion from core team before further action

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#63371 In pandas-dev/pandas;

· galipremsagar opened on Dec 15, 2025

REGR: registered accessors are no longer cached per DataFrame

Accessorsaccessor registration mechanism (not .str, .dt, .cat)accessor registration mechanism (not .str, .dt, .cat)

Needs DiscussionRequires discussion from core team before further actionRequires discussion from core team before further action

Status: Open.

#63393 In pandas-dev/pandas;

· jorisvandenbossche opened on Dec 17, 2025

BUG: 3.0rc0: comparing <code>StringArray</code>s with <code>==</code> yields a <code>bool[pyarrow]</code> array with no <code>.sum()</code> method

API - ConsistencyInternal Consistency of API/BehaviorInternal Consistency of API/Behavior

Arrowpyarrow functionalitypyarrow functionality

Bug

Status: Open.

#63458 In pandas-dev/pandas;

· flying-sheep opened on Dec 22, 2025

String dtype: differences in regex operations because of engine (Python vs RE2)

API - ConsistencyInternal Consistency of API/BehaviorInternal Consistency of API/Behavior

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#63683 In pandas-dev/pandas;

· jorisvandenbossche opened on Jan 14, 2026

BUG: bug in pandas 3.0 with posixpath inside Series

Arrowpyarrow functionalitypyarrow functionality

Bug

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#63832 In pandas-dev/pandas;

· vadimpy opened on Jan 23, 2026

BUG: Preserve StringDtype in where with list-like other

Bug

ConditionalsE.g. where, mask, case_whenE.g. where, mask, case_when

StringsString extension data type and string dataString extension data type and string data

Status: Open (in progress).

pandas-dev/pandasnumber 64040

#64040 In pandas-dev/pandas;

· sanrishi opened on Feb 5, 2026

BUG: str.find returns byte offset instead of character offset with str dtype

Arrowpyarrow functionalitypyarrow functionality

Bug

StringsString extension data type and string dataString extension data type and string data

Status: Open (in progress).

pandas-dev/pandasnumber 64133

#64133 In pandas-dev/pandas;

· Mr-Neutr0n opened on Feb 13, 2026

DOC: wrong source link for <code>pandas.DataFrame</code>

Docs

Status: Open.

#64224 In pandas-dev/pandas;

· wjandrea opened on Feb 18, 2026

BUG: Assigning pd.NA to StringDtype column causes "Unknown error: Wrapping .. failed" after pd.concat with PyArrow

Arrowpyarrow functionalitypyarrow functionality

Bug

StringsString extension data type and string dataString extension data type and string data

Status: Open.

#64320 In pandas-dev/pandas;

· askalonso opened on Feb 26, 2026