From 141c47997b19bdbb5638ca04212db3d81a94bb81 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <rhettinger@users.noreply.github.com>
Date: Fri, 23 Dec 2022 15:52:16 -0800
Subject: [PATCH] Add "strict" to dotproduct(). Add docstring. Factor-out
common code. (GH-100480) (cherry picked from commit
f89de679ffec35e82548341cb23e675546602288)
Co-authored-by: Raymond Hettinger <rhettinger@users.noreply.github.com>
---
Doc/library/itertools.rst | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 8eb843ab0a67be..371f7c1fdcd453 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -795,7 +795,8 @@ which incur interpreter overhead.
return chain.from_iterable(repeat(tuple(iterable), n))
def dotproduct(vec1, vec2):
- return sum(map(operator.mul, vec1, vec2))
+ "Compute a sum of products."
+ return sum(starmap(operator.mul, zip(vec1, vec2, strict=True)))
def convolve(signal, kernel):
# See: https://betterexplained.com/articles/intuitive-convolution/
@@ -807,7 +808,7 @@ which incur interpreter overhead.
window = collections.deque([0], maxlen=n) * n
for x in chain(signal, repeat(0, n-1)):
window.append(x)
- yield sum(map(operator.mul, kernel, window))
+ yield dotproduct(kernel, window)
def polynomial_from_roots(roots):
"""Compute a polynomial's coefficients from its roots.