From c42c76cb841a47b47528ec6b9bfc47467aec1350 Mon Sep 17 00:00:00 2001 From: Stuart Berg Date: Mon, 12 Aug 2019 11:27:49 -0400 Subject: [PATCH] DOC: Clarify that unique() promotes dtype to 64-bit --- pandas/core/algorithms.py | 1 + pandas/core/indexes/base.py | 1 + pandas/core/series.py | 5 +++-- 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/pandas/core/algorithms.py b/pandas/core/algorithms.py index 21d12d02c9008..5cc3afbae92d3 100644 --- a/pandas/core/algorithms.py +++ b/pandas/core/algorithms.py @@ -320,6 +320,7 @@ def unique(values): of appearance. This does NOT sort. Significantly faster than numpy.unique. Includes NA values. + For numeric input, the dtype of the result will be promoted to 64-bit. Parameters ---------- diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py index 598c4dca9ce88..b669475531f10 100644 --- a/pandas/core/indexes/base.py +++ b/pandas/core/indexes/base.py @@ -2122,6 +2122,7 @@ def dropna(self, how="any"): Returns ------- Index without duplicates + For numeric input, the dtype of the result will be promoted to 64-bit. See Also -------- diff --git a/pandas/core/series.py b/pandas/core/series.py index 4e64a25e430eb..a3f0bfaaf8fd0 100644 --- a/pandas/core/series.py +++ b/pandas/core/series.py @@ -1910,8 +1910,9 @@ def unique(self): Notes ----- - Returns the unique values as a NumPy array. In case of an - extension-array backed Series, a new + Returns the unique values as a NumPy array. + For numeric input, the dtype of the result will be promoted to 64-bit. + In case of an extension-array backed Series, a new :class:`~api.extensions.ExtensionArray` of that type with just the unique values is returned. This includes