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BUG: concat of all-nan with empty frame produces object dtype

good first issue

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

Status: Closed (completed).

#9188 In pandas-dev/pandas;

· by jreback was closed on May 10, 2021

combine_first not retaining dtypes

Bug

Dtype ConversionsUnexpected or buggy dtype conversionsUnexpected or buggy dtype conversions

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

Status: Closed (completed).

#7509 In pandas-dev/pandas;

· by altaurog was closed on Jan 15, 2021

additional keys in groupby indices when NAs are present

Bug

Groupby

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

Status: Closed (completed).

#9304 In pandas-dev/pandas;

· by josepm was closed on Jan 1, 2021

BUG: loc.__setitem__ over MultiIndex with slice key and step != 1 does strange things

good first issue

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

Status: Closed (completed).

#8856 In pandas-dev/pandas;

· by immerrr was closed on May 10, 2021

Regression in casting Series to DataFrame with .name='foo' and columns=['bar']

ConstructorsSeries/DataFrame/Index/pd.array ConstructorsSeries/DataFrame/Index/pd.array Constructors

good first issue

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

Status: Closed (completed).

#7893 In pandas-dev/pandas;

· by qwhelan was closed on May 10, 2021

BUG: NaN level values in stack() and unstack()

good first issue

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

Status: Closed (completed).

#9406 In pandas-dev/pandas;

· by seth-p was closed on May 10, 2021

Aligning on multi-index with swapped levels gives unclear error message

good first issue

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

Status: Closed (completed).

#9952 In pandas-dev/pandas;

· by jorisvandenbossche was closed on May 10, 2021

BUG/COMPAT: Series bool type not promoted to object when introducing NaNs

good first issue

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

Status: Closed (completed).

#13034 In pandas-dev/pandas;

· by domspad was closed on May 12, 2021

API: should the RangeIndex constructor accept start=range_index?

API Design

ConstructorsSeries/DataFrame/Index/pd.array ConstructorsSeries/DataFrame/Index/pd.array Constructors

Enhancement

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

Status: Closed (completed).

#12067 In pandas-dev/pandas;

· by shoyer was closed on Mar 9, 2021

ERR: stricter checks on Index construction when tz is passed

API Design

ConstructorsSeries/DataFrame/Index/pd.array ConstructorsSeries/DataFrame/Index/pd.array Constructors

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

TimezonesTimezone data dtypeTimezone data dtype

Status: Closed (completed).

#14093 In pandas-dev/pandas;

· by jreback was closed on Dec 22, 2020

BUG: unstack doesn't preserve categorical dtype

good first issue

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

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

Status: Closed (completed).

#14018 In pandas-dev/pandas;

· by pijucha was closed on May 17, 2021

BUG: groupby, as_index=False still returning group variable as index

Bug

good first issue

Groupby

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

Status: Closed (completed).

#13217 In pandas-dev/pandas;

· by nickeubank was closed on May 12, 2021

ENH: guarantee pandas.Series.value_counts "sort=False" to be original ordering

AlgosNon-arithmetic algos: value_counts, factorize, sorting, isin, clip, shift, diffNon-arithmetic algos: value_counts, factorize, sorting, isin, clip, shift, diff

Enhancement

Status: Closed (completed).

#12679 In pandas-dev/pandas;

· by rchurt was closed on Jan 22, 2021

error merging dataframes with unicode and numpy.float64 column names

good first issue

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

Status: Closed (completed).

#13353 In pandas-dev/pandas;

· by corakingdon was closed on May 12, 2021

ENH: write Styler rendered output to file

Enhancement

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

Stylerconditional formatting using DataFrame.styleconditional formatting using DataFrame.style

Status: Closed (completed).

#13379 In pandas-dev/pandas;

· by jorisvandenbossche was closed on May 26, 2021

enhancement: add optional row/col paramater to to_latex formatter

Enhancement

IO LaTeXto_latexto_latex

Status: Closed (completed).

#13203 In pandas-dev/pandas;

· by nbecker was closed on May 24, 2021

BUG: PeriodIndex construction fails (or produces erroneous result) with memoryview as input.

ConstructorsSeries/DataFrame/Index/pd.array ConstructorsSeries/DataFrame/Index/pd.array Constructors

good first issue

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

Status: Closed (completed).

#13120 In pandas-dev/pandas;

· by ssanderson was closed on May 12, 2021

Series.any() and .all() don't return bool values if dtype=object

Bug

Dtype ConversionsUnexpected or buggy dtype conversionsUnexpected or buggy dtype conversions

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

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

Status: Closed (completed).

#12863 In pandas-dev/pandas;

· by jdavies1618 was closed on May 6, 2021

Column reappears after drop() when working on a reference of that column

good first issue

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

Status: Closed (completed).

#13934 In pandas-dev/pandas;

· by Gunthard was closed on May 17, 2021

BUG: Columns used in sum on 1 row dataframe depend on values instead of dtype

good first issue

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

Status: Closed (completed).

#13912 In pandas-dev/pandas;

· by jcrist was closed on May 17, 2021

Partial indexing with a list and hierarchical index

good first issue

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

Status: Closed (completed).

#13501 In pandas-dev/pandas;

· by jseabold was closed on May 17, 2021

BUG: duplicate indexing on non-integer index with positional indexers failing in py3

good first issue

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

Status: Closed (completed).

#13427 In pandas-dev/pandas;

· by alexanderwhatley was closed on May 17, 2021

BUG: Index set operations issues

good first issue

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

Status: Closed (completed).

#13432 In pandas-dev/pandas;

· by pijucha was closed on May 17, 2021

Dataframe pivot_table() returning a multi-index for a single value, empty dataframe

Bug

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

Status: Closed (completed).

#13483 In pandas-dev/pandas;

· by amanhanda was closed on Feb 24, 2021

frame and columns can get out of sync

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).

#13569 In pandas-dev/pandas;

· by dsm054 was closed on May 17, 2021