https://github.com/python/cpython/commit/cc5cd4d93e3e079e897da9ceb1732ef16d7... commit: cc5cd4d93e3e079e897da9ceb1732ef16d79d01b branch: main author: Raymond Hettinger <rhettinger@users.noreply.github.com> committer: rhettinger <rhettinger@users.noreply.github.com> date: 2024-05-31T17:08:55-05:00 summary: statistics.fmean(): speed-up code path for non-sizeable inputs. (gh-119876) files: M Lib/statistics.py diff --git a/Lib/statistics.py b/Lib/statistics.py index c2f4fe8e054d3d..450edfaabe8def 100644 --- a/Lib/statistics.py +++ b/Lib/statistics.py @@ -505,13 +505,11 @@ def fmean(data, weights=None): n = len(data) except TypeError: # Handle iterators that do not define __len__(). - n = 0 - def count(iterable): - nonlocal n - for n, x in enumerate(iterable, start=1): - yield x - data = count(data) - total = fsum(data) + counter = count() + total = fsum(map(itemgetter(0), zip(data, counter))) + n = next(counter) + else: + total = fsum(data) if not n: raise StatisticsError('fmean requires at least one data point') return total / n