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BUG: Summation of NaT in a DataFrame with axis=1 does not return NaT

Bug

DatetimeDatetime data dtypeDatetime data dtype

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

Numeric OperationsArithmetic, Comparison, and Logical operationsArithmetic, Comparison, and Logical operations

Reduction Operationssum, mean, min, max, etc.sum, mean, min, max, etc.

Status: Closed (completed).

#17235 In pandas-dev/pandas;

· by s-celles was closed on Oct 24, 2020

read_csv returns different float values for same number

IO CSVread_csv, to_csvread_csv, to_csv

Status: Closed (completed).

#17154 In pandas-dev/pandas;

· by chrisyeh96 was closed on Sep 13, 2020

ENH: support .groupby().ewm() directly

Enhancement

Groupby

Windowrolling, ewma, expandingrolling, ewma, expanding

Status: Closed (completed).

#16037 In pandas-dev/pandas;

· by jreback was closed on Nov 18, 2020

AttributeError when slicing a datetime MultiIndex level

Bug

MultiIndex

Needs TestsUnit test(s) needed to prevent regressionsUnit test(s) needed to prevent regressions

Status: Closed (completed).

#15928 In pandas-dev/pandas;

· by toobaz was closed on Oct 20, 2020

ERR: left_index AND left_on or right_index AND right_on should raise

Error ReportingIncorrect or improved errors from pandasIncorrect or improved errors from pandas

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

Status: Closed (completed).

#16228 In pandas-dev/pandas;

· by Satyadev592 was closed on Nov 8, 2020

Column loses category when using .loc for a one row dataframe

CategoricalCategorical Data TypeCategorical Data Type

good first issue

IndexingRelated to indexing on series/frames, not to indexes themselvesRelated to indexing on series/frames, not to indexes themselves

Needs TestsUnit test(s) needed to prevent regressionsUnit test(s) needed to prevent regressions

Status: Closed (completed).

#16360 In pandas-dev/pandas;

· by nyejon was closed on Nov 23, 2020

"cannot reindex from a duplicate axis" when groupby().apply() on MultiIndex columns

ApplyApply, Aggregate, Transform, MapApply, Aggregate, Transform, Map

Bug

Groupby

MultiIndex

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

Status: Closed (completed).

#16646 In pandas-dev/pandas;

· by bdforbes was closed on Aug 6, 2020

DataFrameGroupBy.boxplot with subplots=False fails when using column param

Groupby

Visualizationplottingplotting

Status: Closed (completed).

#16748 In pandas-dev/pandas;

· by tdpetrou was closed on Nov 8, 2020

DataFrame.replace: TypeError: Cannot compare types 'ndarray(dtype=int64)' and 'unicode'

good first issue

Needs TestsUnit test(s) needed to prevent regressionsUnit test(s) needed to prevent regressions

Numeric OperationsArithmetic, Comparison, and Logical operationsArithmetic, Comparison, and Logical operations

UnicodeUnicode stringsUnicode strings

Status: Closed (completed).

#16784 In pandas-dev/pandas;

· by eromoe was closed on Sep 7, 2020

BUG: Period with nanoseconds (?)

API Design

Bug

PeriodPeriod data typePeriod data type

Status: Closed (completed).

#17053 In pandas-dev/pandas;

· by ChadFulton was closed on Dec 2, 2020

Reading binary file handle (mode "rb") doesn't work with read_fwf

Bug

IO Fixed Widthread_fwfread_fwf

Status: Closed (completed).

#18035 In pandas-dev/pandas;

· by prcastro was closed on Sep 30, 2020

BENCH: Index.take benchmark is measuring wrong thing

BenchmarkPerformance (ASV) benchmarksPerformance (ASV) benchmarks

good first issue

Status: Closed (completed).

#18000 In pandas-dev/pandas;

· by jorisvandenbossche was closed on Oct 2, 2020

BUG: Pandas groupby indices behaving diferrently with 2 and 3 rows

Groupby

Needs TestsUnit test(s) needed to prevent regressionsUnit test(s) needed to prevent regressions

Status: Closed (completed).

#18451 In pandas-dev/pandas;

· by mcdallas was closed on Aug 3, 2020

s.loc[[]] raises error (only) if index is not unique

Bug

IndexingRelated to indexing on series/frames, not to indexes themselvesRelated to indexing on series/frames, not to indexes themselves

MultiIndex

Status: Closed (completed).

#13691 In pandas-dev/pandas;

· by toobaz was closed on Oct 16, 2020

Calling shift(n != 0) on an empty DatetimeIndex raises an IndexError

Bug

DatetimeDatetime data dtypeDatetime data dtype

Status: Closed (completed).

#14811 In pandas-dev/pandas;

· by chazmo03 was closed on Sep 30, 2020

Series.to_string ignores empty lines at the start/end when index=False

Bug

good first issue

IO DataIO issues that don't fit into a more specific labelIO issues that don't fit into a more specific label

Needs TestsUnit test(s) needed to prevent regressionsUnit test(s) needed to prevent regressions

Output-Formatting__repr__ of pandas objects, to_string__repr__ of pandas objects, to_string

Status: Closed (completed).

#13653 In pandas-dev/pandas;

· by alberthdev was closed on Sep 30, 2020

to_html ignores na_rep when float_format set

Bug

IO HTMLread_html, to_html, Styler.apply, Styler.applymapread_html, to_html, Styler.apply, Styler.applymap

Output-Formatting__repr__ of pandas objects, to_string__repr__ of pandas objects, to_string

Status: Closed (completed).

#13828 In pandas-dev/pandas;

· by paulperry was closed on Oct 24, 2020

PERF: asv for select_dtypes

Dtype ConversionsUnexpected or buggy dtype conversionsUnexpected or buggy dtype conversions

good first issue

PerformanceMemory or execution speed performanceMemory or execution speed performance

Status: Closed (completed).

#14588 In pandas-dev/pandas;

· by simonm3 was closed on Oct 5, 2020

API: Index.append behaviour with categoricals

API Design

CategoricalCategorical Data TypeCategorical Data Type

Enhancement

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

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

Status: Closed (completed).

#14586 In pandas-dev/pandas;

· by jorisvandenbossche was closed on Nov 29, 2020

Categorical.__setitem__ doesn't handle setting tuples

Bug

CategoricalCategorical Data TypeCategorical Data Type

Enhancement

IndexingRelated to indexing on series/frames, not to indexes themselvesRelated to indexing on series/frames, not to indexes themselves

Nested DataData where the values are collections (lists, sets, dicts, objects, etc.).Data where the values are collections (lists, sets, dicts, objects, etc.).

Status: Closed (completed).

#20439 In pandas-dev/pandas;

· by TomAugspurger was closed on Oct 2, 2020

pd.to_datetime, unit='s' much slower for float64 than for int64

DatetimeDatetime data dtypeDatetime data dtype

PerformanceMemory or execution speed performanceMemory or execution speed performance

Status: Closed (completed).

#20445 In pandas-dev/pandas;

· by bchu was closed on Sep 19, 2020

BUG: HDFStore failures on timezone-aware data

Bug

IO HDF5read_hdf, HDFStoreread_hdf, HDFStore

Status: Closed (completed).

#20594 In pandas-dev/pandas;

· by adshieh was closed on Oct 15, 2020

pandas.DataFrame.rolling produces incorrect value if integer and float objects are mixed

Bug

Windowrolling, ewma, expandingrolling, ewma, expanding

Status: Closed (completed).

#20649 In pandas-dev/pandas;

· by mustafaburny was closed on Sep 19, 2020

Inconsistent MultiIndex behaviour when indexing selects no rows

IndexingRelated to indexing on series/frames, not to indexes themselvesRelated to indexing on series/frames, not to indexes themselves

MultiIndex

Status: Closed (completed).

#19556 In pandas-dev/pandas;

· by lauhayden was closed on Nov 21, 2020

CLN: Standardize values coercion during Block initialization

Clean

InternalsRelated to non-user accessible pandas implementationRelated to non-user accessible pandas implementation

RefactorInternal refactoring of codeInternal refactoring of code

Status: Closed (completed).

#19492 In pandas-dev/pandas;

· by TomAugspurger was closed on Oct 9, 2020