From bfd68bf4ac6661bf0fab51178583bee88840a8e6 Mon Sep 17 00:00:00 2001 From: Nick Coghlan Date: Sat, 8 Feb 2014 19:44:16 +1000 Subject: [PATCH] Issue #20478: avoid special casing Counter in statistics Passing Counter objects to the Counter constructor is special cased, going through iter() firsts ensures they are handled the same way as any other iterable. (Committing on Steven's behalf as I don't believe his SSH key is registered yet) --- Lib/statistics.py | 4 +--- Lib/test/test_statistics.py | 8 ++++++++ Misc/NEWS | 3 +++ 3 files changed, 12 insertions(+), 3 deletions(-) diff --git a/Lib/statistics.py b/Lib/statistics.py index a67a6d11cd..9359ed71e5 100644 --- a/Lib/statistics.py +++ b/Lib/statistics.py @@ -268,9 +268,7 @@ def _coerce_types(T1, T2): def _counts(data): # Generate a table of sorted (value, frequency) pairs. - if data is None: - raise TypeError('None is not iterable') - table = collections.Counter(data).most_common() + table = collections.Counter(iter(data)).most_common() if not table: return table # Extract the values with the highest frequency. diff --git a/Lib/test/test_statistics.py b/Lib/test/test_statistics.py index 3d30d88f69..6db821fc6e 100644 --- a/Lib/test/test_statistics.py +++ b/Lib/test/test_statistics.py @@ -1355,6 +1355,14 @@ class TestMode(NumericTestCase, AverageMixin, UnivariateTypeMixin): # collections.Counter, which accepts None and returns an empty dict. self.assertRaises(TypeError, self.func, None) + def test_counter_data(self): + # Test that a Counter is treated like any other iterable. + data = collections.Counter([1, 1, 1, 2]) + # Since the keys of the counter are treated as data points, not the + # counts, this should raise. + self.assertRaises(statistics.StatisticsError, self.func, data) + + # === Tests for variances and standard deviations === diff --git a/Misc/NEWS b/Misc/NEWS index 58938e0e01..9f8f43c7cb 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -24,6 +24,9 @@ Core and Builtins Library ------- +- Issue #20478: the statistics module now treats collections.Counter inputs + like any other iterable. + - Issue #17369: get_filename was raising an exception if the filename parameter's RFC2231 encoding was broken in certain ways. This was a regression relative to python2. -- 2.40.0