From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Thu, 28 May 2020 16:58:33 +0000 (-0700)
Subject: bpo-40806: itertools.product immediately consumes its inputs (GH-20492) (GH-20498)
X-Git-Tag: v3.9.0b2~58
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e4cc3a7c1f5ba9ea2c3015a5bf09cb5b93db5d47;p=thirdparty%2FPython%2Fcpython.git

bpo-40806: itertools.product immediately consumes its inputs (GH-20492) (GH-20498)
---

diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
index 3e5a67389810..3c94c4b35dc0 100644
--- a/Doc/library/itertools.rst
+++ b/Doc/library/itertools.rst
@@ -563,6 +563,9 @@ loops that truncate the stream.
            for prod in result:
                yield tuple(prod)
 
+   Before :func:`product` runs, it completely consumes the input iterables,
+   keeping pools of values in memory to generate the products.  Accordingly,
+   it only useful with finite inputs.
 
 .. function:: repeat(object[, times])