Link to "yield from" examples in yield documentation.
This commit also simplifies the more advanced "yield from" example and removes
unused function parameters.
diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst
index 4b9dc9c..4ea4995 100644
--- a/Doc/whatsnew/3.3.rst
+++ b/Doc/whatsnew/3.3.rst
@@ -393,14 +393,18 @@
PEP written and implemented by Antoine Pitrou
+.. index::
+ single: yield; yield from (in What's New)
+
.. _pep-380:
PEP 380: Syntax for Delegating to a Subgenerator
================================================
-PEP 380 adds the ``yield from`` expression, allowing a generator to delegate
+PEP 380 adds the ``yield from`` expression, allowing a :term:`generator` to
+delegate
part of its operations to another generator. This allows a section of code
-containing 'yield' to be factored out and placed in another generator.
+containing :keyword:`yield` to be factored out and placed in another generator.
Additionally, the subgenerator is allowed to return with a value, and the
value is made available to the delegating generator.
@@ -421,15 +425,15 @@
receive sent and thrown values directly from the calling scope, and
return a final value to the outer generator::
- >>> def accumulate(start=0):
- ... tally = start
+ >>> def accumulate():
+ ... tally = 0
... while 1:
... next = yield
... if next is None:
... return tally
... tally += next
...
- >>> def gather_tallies(tallies, start=0):
+ >>> def gather_tallies(tallies):
... while 1:
... tally = yield from accumulate()
... tallies.append(tally)
@@ -437,7 +441,7 @@
>>> tallies = []
>>> acc = gather_tallies(tallies)
>>> next(acc) # Ensure the accumulator is ready to accept values
- >>> for i in range(10):
+ >>> for i in range(4):
... acc.send(i)
...
>>> acc.send(None) # Finish the first tally
@@ -446,7 +450,7 @@
...
>>> acc.send(None) # Finish the second tally
>>> tallies
- [45, 10]
+ [6, 10]
The main principle driving this change is to allow even generators that are
designed to be used with the ``send`` and ``throw`` methods to be split into