From 2314c7e88c21b943ceb3ebf717d304ac74e9f056 Mon Sep 17 00:00:00 2001 From: William Wai Lim Chan Date: Sun, 15 Aug 2021 14:55:07 -0400 Subject: [PATCH 1/3] fixed transform docs --- pandas/core/groupby/groupby.py | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/pandas/core/groupby/groupby.py b/pandas/core/groupby/groupby.py index aad43e4f96b81..211698aae5e1d 100644 --- a/pandas/core/groupby/groupby.py +++ b/pandas/core/groupby/groupby.py @@ -318,14 +318,13 @@ class providing the base-class of operations. """ _transform_template = """ -Call function producing a like-indexed %(klass)s on each group and -return a %(klass)s having the same indexes as the original object -filled with the transformed values +Apply function ``func`` column-by-column to the GroupBy object and return a %(klass)s with +the same length as the group. Parameters ---------- -f : function - Function to apply to each group. +func : function + Function to apply to each column within each group. Can also accept a Numba JIT function with ``engine='numba'`` specified. @@ -375,16 +374,16 @@ class providing the base-class of operations. Each group is endowed the attribute 'name' in case you need to know which group you are working on. -The current implementation imposes three requirements on f: +The current implementation imposes three requirements on func: -* f must return a value that either has the same shape as the input +* func must return a value that either has the same shape as the input subframe or can be broadcast to the shape of the input subframe. - For example, if `f` returns a scalar it will be broadcast to have the + For example, if `func` returns a scalar it will be broadcast to have the same shape as the input subframe. -* if this is a DataFrame, f must support application column-by-column - in the subframe. If f also supports application to the entire subframe, +* func must support application column-by-column + in the subframe. If func also supports application to the entire subframe, then a fast path is used starting from the second chunk. -* f must not mutate groups. Mutation is not supported and may +* func must not mutate groups. Mutation is not supported and may produce unexpected results. See :ref:`gotchas.udf-mutation` for more details. When using ``engine='numba'``, there will be no "fall back" behavior internally. From 624d6b7a300cd7abd8afd86c974e4bb058dc327f Mon Sep 17 00:00:00 2001 From: William Wai Lim Chan Date: Sun, 15 Aug 2021 14:57:08 -0400 Subject: [PATCH 2/3] fixed linting issues --- pandas/core/groupby/groupby.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/pandas/core/groupby/groupby.py b/pandas/core/groupby/groupby.py index 211698aae5e1d..7a438af4a335e 100644 --- a/pandas/core/groupby/groupby.py +++ b/pandas/core/groupby/groupby.py @@ -318,8 +318,8 @@ class providing the base-class of operations. """ _transform_template = """ -Apply function ``func`` column-by-column to the GroupBy object and return a %(klass)s with -the same length as the group. +Apply function ``func`` column-by-column to the GroupBy object and return a %(klass)s +with the same length as the group. Parameters ---------- From d203abfe351d83d22d29c2bd156f1edc926587f5 Mon Sep 17 00:00:00 2001 From: William Wai Lim Chan Date: Tue, 17 Aug 2021 12:34:32 -0400 Subject: [PATCH 3/3] replaced length with index --- pandas/core/groupby/groupby.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/pandas/core/groupby/groupby.py b/pandas/core/groupby/groupby.py index 7a438af4a335e..1d0d3bcc394ab 100644 --- a/pandas/core/groupby/groupby.py +++ b/pandas/core/groupby/groupby.py @@ -319,7 +319,7 @@ class providing the base-class of operations. _transform_template = """ Apply function ``func`` column-by-column to the GroupBy object and return a %(klass)s -with the same length as the group. +with the same number of indices as the group. Parameters ----------