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.
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index c8c9b46..17705b1 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -478,8 +478,8 @@
.. 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