From be769f262aa58cc49246f7e6957ef399a0097ae6 Mon Sep 17 00:00:00 2001 From: Simon Hawkins Date: Mon, 17 Aug 2020 20:25:48 +0100 Subject: [PATCH 1/2] REGR: follow-up to return copy with df.interpolate on empty DataFrame --- pandas/core/generic.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/pandas/core/generic.py b/pandas/core/generic.py index 9cbe2f714fd57..fe412bc0ce937 100644 --- a/pandas/core/generic.py +++ b/pandas/core/generic.py @@ -6893,7 +6893,7 @@ def interpolate( obj = self.T if should_transpose else self if obj.empty: - return self + return self.copy() if method not in fillna_methods: axis = self._info_axis_number From 6fefb5beecdac48359a073bc37b112b3ee383336 Mon Sep 17 00:00:00 2001 From: Simon Hawkins Date: Tue, 18 Aug 2020 10:29:11 +0100 Subject: [PATCH 2/2] assert result is not df --- pandas/tests/frame/methods/test_interpolate.py | 1 + 1 file changed, 1 insertion(+) diff --git a/pandas/tests/frame/methods/test_interpolate.py b/pandas/tests/frame/methods/test_interpolate.py index 3c9d79397e4bd..6b86a13fcf1b9 100644 --- a/pandas/tests/frame/methods/test_interpolate.py +++ b/pandas/tests/frame/methods/test_interpolate.py @@ -38,6 +38,7 @@ def test_interp_empty(self): # https://github.com/pandas-dev/pandas/issues/35598 df = DataFrame() result = df.interpolate() + assert result is not df expected = df tm.assert_frame_equal(result, expected)