From 7d14015e629da702f17d5e0ab616c15c8145e771 Mon Sep 17 00:00:00 2001
From: Andrew Svetlov <andrew.svetlov@gmail.com>
Date: Sat, 6 Oct 2012 17:11:45 +0300
Subject: [PATCH] Issue #16120: Use |yield from| in stdlib.

Patch by Berker Peksag.
---
 Lib/lib2to3/btm_utils.py | 6 ++----
 Lib/lib2to3/pytree.py    | 9 +++------
 Lib/unittest/loader.py   | 3 +--
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/Lib/lib2to3/btm_utils.py b/Lib/lib2to3/btm_utils.py
index 2276dc9e96..339750edba 100644
--- a/Lib/lib2to3/btm_utils.py
+++ b/Lib/lib2to3/btm_utils.py
@@ -96,8 +96,7 @@ class MinNode(object):
     def leaves(self):
         "Generator that returns the leaves of the tree"
         for child in self.children:
-            for x in child.leaves():
-                yield x
+            yield from child.leaves()
         if not self.children:
             yield self
 
@@ -277,7 +276,6 @@ def rec_test(sequence, test_func):
     sub-iterables"""
     for x in sequence:
         if isinstance(x, (list, tuple)):
-            for y in rec_test(x, test_func):
-                yield y
+            yield from rec_test(x, test_func)
         else:
             yield test_func(x)
diff --git a/Lib/lib2to3/pytree.py b/Lib/lib2to3/pytree.py
index 17cbf0a2f9..c4a1be3500 100644
--- a/Lib/lib2to3/pytree.py
+++ b/Lib/lib2to3/pytree.py
@@ -194,8 +194,7 @@ class Base(object):
 
     def leaves(self):
         for child in self.children:
-            for x in child.leaves():
-                yield x
+            yield from child.leaves()
 
     def depth(self):
         if self.parent is None:
@@ -274,16 +273,14 @@ class Node(Base):
     def post_order(self):
         """Return a post-order iterator for the tree."""
         for child in self.children:
-            for node in child.post_order():
-                yield node
+            yield from child.post_order()
         yield self
 
     def pre_order(self):
         """Return a pre-order iterator for the tree."""
         yield self
         for child in self.children:
-            for node in child.pre_order():
-                yield node
+            yield from child.pre_order()
 
     def _prefix_getter(self):
         """
diff --git a/Lib/unittest/loader.py b/Lib/unittest/loader.py
index 541884e416..a5ac737fc2 100644
--- a/Lib/unittest/loader.py
+++ b/Lib/unittest/loader.py
@@ -291,8 +291,7 @@ class TestLoader(object):
                         # tests loaded from package file
                         yield tests
                     # recurse into the package
-                    for test in self._find_tests(full_path, pattern):
-                        yield test
+                    yield from self._find_tests(full_path, pattern)
                 else:
                     try:
                         yield load_tests(self, tests, pattern)
-- 
2.50.1