Issue #7830: Flatten nested functools.partial.
diff --git a/Lib/functools.py b/Lib/functools.py
index 20a26f9..91e9685 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -241,6 +241,14 @@
"""New function with partial application of the given arguments
and keywords.
"""
+ if hasattr(func, 'func'):
+ args = func.args + args
+ tmpkw = func.keywords.copy()
+ tmpkw.update(keywords)
+ keywords = tmpkw
+ del tmpkw
+ func = func.func
+
def newfunc(*fargs, **fkeywords):
newkeywords = keywords.copy()
newkeywords.update(fkeywords)
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 55b96b4..c549ac4 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -131,6 +131,16 @@
join = self.partial(''.join)
self.assertEqual(join(data), '0123456789')
+ def test_nested_optimization(self):
+ partial = self.partial
+ # Only "true" partial is optimized
+ if partial.__name__ != 'partial':
+ return
+ inner = partial(signature, 'asdf')
+ nested = partial(inner, bar=True)
+ flat = partial(signature, 'asdf', bar=True)
+ self.assertEqual(signature(nested), signature(flat))
+
@unittest.skipUnless(c_functools, 'requires the C _functools module')
class TestPartialC(TestPartial, unittest.TestCase):