bpo-37158: Simplify and speed-up statistics.fmean() (GH-13832)

6c01ebcc · Raymond Hettinger · GitHub · ccf0efbb · 6c01ebcc · 6c01ebcc
Commit 6c01ebcc authored Jun 05, 2019 by Raymond Hettinger Committed by GitHub Jun 05, 2019
Hide whitespace changes
Inline Side-by-side

Showing with 5 additions and 4 deletions

Lib/statistics.py Lib/statistics.py +4 -4

Misc/NEWS.d/next/Library/2019-06-04-22-25-38.bpo-37158.JKm15S.rst ...S.d/next/Library/2019-06-04-22-25-38.bpo-37158.JKm15S.rst +1 -0

No files found.
--- a/Lib/statistics.py
+++ b/Lib/statistics.py
@@ -320,11 +320,11 @@ def fmean(data):
    except TypeError:
        # Handle iterators that do not define __len__().
        n = 0
-        def count(x):
+        def count(iterable):
            nonlocal n
-            n += 1
+            for n, x in enumerate(iterable, start=1):
-            return x
+                yield x
-        total = fsum(map(count, data))
+        total = fsum(count(data))
    else:
        total = fsum(data)
    try:

--- a/Misc/NEWS.d/next/Library/2019-06-04-22-25-38.bpo-37158.JKm15S.rst
+++ b/Misc/NEWS.d/next/Library/2019-06-04-22-25-38.bpo-37158.JKm15S.rst
+Speed-up statistics.fmean() by switching from a function to a generator.