bpo-27646: Say that 'yield from' expression can be any iterable (GH-24595)

Previously, the doc at least strongly implied that it had to be an iterator.
(cherry picked from commit 2f9ef514fb24b6a95bd3272885f197752810c107)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index 81dd6fc860355fbab8e004794fb381db6d14b44e..0ac45995aef9c47f8cf6f8b1eceef399e07b6e01 100644 (file)
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -476,8 +476,8 @@ allowing any pending :keyword:`finally` clauses to execute.
 .. index::
    single: from; yield from expression
 
-When ``yield from <expr>`` is used, it treats the supplied expression as
-a subiterator. All values produced by that subiterator are passed directly
+When ``yield from <expr>`` is used, the supplied expression must be an
+iterable. The values produced by iterating that iterable are passed directly
 to the caller of the current generator's methods. Any values passed in with
 :meth:`~generator.send` and any exceptions passed in with
 :meth:`~generator.throw` are passed to the underlying iterator if it has the

diff --git a/Misc/NEWS.d/next/Documentation/2021-02-20-00-09-13.bpo-27646.HRsmo-.rst b/Misc/NEWS.d/next/Documentation/2021-02-20-00-09-13.bpo-27646.HRsmo-.rst
new file mode 100644 (file)
index 0000000..8ba398a
--- /dev/null
+++ b/Misc/NEWS.d/next/Documentation/2021-02-20-00-09-13.bpo-27646.HRsmo-.rst
@@ -0,0 +1,2 @@
+Clarify that 'yield from <expr>' works with any iterable, not just
+iterators.