Issues

• CI: Nightly wheel builds are failing

  CI
  pandas-dev/pandas#71036 · Filter by author github-actions opened on Oct 11, 2026

• BUG: read_csv(engine="pyarrow") takes the column count from the first row, not from names

  Needs Triage
  pandas-dev/pandas#71034 · Filter by author djouallah opened on Oct 11, 2026

• BUG: Index comparison with itself skips nullable dtype semantics (numpy bool instead of boolean with NA)

  BugNeeds Triage
  pandas-dev/pandas#71022 · Filter by author SudoKMaar opened on Oct 10, 2026
  2

• BUG: str.contains/match/fullmatch/count with \s on pyarrow-backed strings miss \v and \x1c-\x1f

  BugNeeds TriageStrings
  pandas-dev/pandas#70991 · Filter by author maharanay22 opened on Oct 10, 2026
  3

  

• CI: pandas-stubs tests fail against pandas nightly

  CITyping
  pandas-dev/pandas#70990 · Filter by author github-actions opened on Oct 10, 2026
  3

  

• PERF: Concatenating many MultiIndexes takes quadratic time since 2.1

  MultiIndexPerformanceReshaping
  pandas-dev/pandas#70884 · Filter by author pablogsal opened on Oct 9, 2026
  3

  

• ENH: Support automatic date and datetime conversion when reading SAS XPORT files

  EnhancementIO SAS
  pandas-dev/pandas#70876 · Filter by author DariuszKamil opened on Oct 9, 2026
  2

  

• BUG: str.get_dummies misinterprets literal separators on object dtype

  BugStrings
  pandas-dev/pandas#70811 · Filter by author AntsiferovBogdan opened on Oct 7, 2026
  2

  

• BUG: str.replace/contains/match/count with \w, \d, \s, \b only match ASCII for default str dtype

  API - ConsistencyBugStrings
  pandas-dev/pandas#70770 · Filter by author maharanay22 opened on Oct 7, 2026 · 3.1
  3

  

• BUG: DataFrame.all/any(skipna=False) raises TypeError for bool[pyarrow] column with NA

  ArrowBugReduction Operations
  pandas-dev/pandas#70685 · Filter by author maharanay22 opened on Oct 6, 2026
  5

  

• DEPR: setting a 2-D value into a single row (df.iloc[1] = np.array([[1, 2]]))

  API DesignDeprecateIndexingNeeds Discussion
  pandas-dev/pandas#70257 · Filter by author jbrockmendel opened on Oct 3, 2026
  1

• BUG: setitem with a 0-d ndarray key raises in iloc/loc

  BugIndexing
  pandas-dev/pandas#70256 · Filter by author jbrockmendel opened on Oct 3, 2026
  3

  

• DOC: clarify and document ODS support in read_excel(), write_excel() and user guide

  DocsIO Excel
  pandas-dev/pandas#70151 · Filter by author stragu opened on Oct 2, 2026
  3

  

• API/DEPR: what does infer_dtype of "mixed-integer" mean?

  API DesignDeprecateNeeds Discussion
  pandas-dev/pandas#70135 · Filter by author jbrockmendel opened on Oct 2, 2026

• BUG: pandas allows comparing complex numbers

  AlgosAPI DesignCompatComplexNeeds DiscussionNumeric Operations
  pandas-dev/pandas#70087 · Filter by author cmp0xff opened on Oct 1, 2026
  3

• DOC: Broken links in documentation

  Docs
  pandas-dev/pandas#70086 · Filter by author github-actions opened on Oct 1, 2026
  3

  

• BUG: iloc assignment raises ValueError: The truth value of a Series is ambiguous with duplicated MultiIndex columns

  BugMultiIndexNeeds Tests
  pandas-dev/pandas#69959 · Filter by author ngxxx307 opened on Sep 30, 2026
  6

  

• BUG: groupby cumsum/cummin/cummax/rank give wrong results for datetime/timedelta columns when a group key is NaN

  BugGroupby
  pandas-dev/pandas#69923 · Filter by author oyiakoumis opened on Sep 29, 2026
  2

  

• API: warn when Timedelta/Datetime gets truncated?

  DatetimeNeeds DiscussionNon-NanoTimedelta
  pandas-dev/pandas#69920 · Filter by author jorisvandenbossche opened on Sep 29, 2026

• DOC: document unit-preserving behaviour in timedelta/datetime arithmetic

  DocsTimedelta
  pandas-dev/pandas#69919 · Filter by author jorisvandenbossche opened on Sep 29, 2026
  4

  

• API: Replace na_action with skipna in map methods

  API DesignApplyNeeds Discussion
  pandas-dev/pandas#69578 · Filter by author rhshadrach opened on Sep 27, 2026
  1

• PERF: df.loc[row, cols] returns a small Series that keeps a (len(cols), len(df)) temporary array alive (regression from 2.x)

  Copy / view semanticsPerformance
  pandas-dev/pandas#69477 · Filter by author rahfar opened on Sep 25, 2026
  3

• BUG: .str and .dt accessors raise on dictionary-encoded ArrowDtype

  pandas-dev/pandas#69462 · Filter by author Sanjays2402 opened on Sep 25, 2026
  1

  

• BUG: to_json(date_format="iso") segfaults on a failed allocation — NpyDateTimeToIsoCallback returns NULL without setting errorMsg

  IO JSONSegfault
  pandas-dev/pandas#69461 · Filter by author Koalk opened on Sep 25, 2026
  1

  

• BUG: loc assignment of a length-1 NumPy array into a PyArrow column raises TypeError

  Bug
  pandas-dev/pandas#69443 · Filter by author hebian1994 opened on Sep 24, 2026 · 3.1
  4