[Python-checkins] cpython: Issue #12428: Add a pure Python implementation of functools.partial().
antoine.pitrou
python-checkins at python.org
Tue Nov 13 21:37:11 CET 2012
http://hg.python.org/cpython/rev/fcfaca024160
changeset: 80421:fcfaca024160
user: Antoine Pitrou <solipsis at pitrou.net>
date: Tue Nov 13 21:35:40 2012 +0100
summary:
Issue #12428: Add a pure Python implementation of functools.partial().
Patch by Brian Thorne.
files:
Lib/functools.py | 28 +++-
Lib/test/test_functools.py | 208 ++++++++++++++++--------
Misc/ACKS | 1 +
Misc/NEWS | 3 +
4 files changed, 167 insertions(+), 73 deletions(-)
diff --git a/Lib/functools.py b/Lib/functools.py
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -11,7 +11,10 @@
__all__ = ['update_wrapper', 'wraps', 'WRAPPER_ASSIGNMENTS', 'WRAPPER_UPDATES',
'total_ordering', 'cmp_to_key', 'lru_cache', 'reduce', 'partial']
-from _functools import partial, reduce
+try:
+ from _functools import reduce
+except ImportError:
+ pass
from collections import namedtuple
try:
from _thread import allocate_lock as Lock
@@ -137,6 +140,29 @@
################################################################################
+### partial() argument application
+################################################################################
+
+def partial(func, *args, **keywords):
+ """new function with partial application of the given arguments
+ and keywords.
+ """
+ def newfunc(*fargs, **fkeywords):
+ newkeywords = keywords.copy()
+ newkeywords.update(fkeywords)
+ return func(*(args + fargs), **newkeywords)
+ newfunc.func = func
+ newfunc.args = args
+ newfunc.keywords = keywords
+ return newfunc
+
+try:
+ from _functools import partial
+except ImportError:
+ pass
+
+
+################################################################################
### LRU Cache function decorator
################################################################################
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -1,4 +1,3 @@
-import functools
import collections
import sys
import unittest
@@ -7,17 +6,31 @@
import pickle
from random import choice
- at staticmethod
-def PythonPartial(func, *args, **keywords):
- 'Pure Python approximation of partial()'
- def newfunc(*fargs, **fkeywords):
- newkeywords = keywords.copy()
- newkeywords.update(fkeywords)
- return func(*(args + fargs), **newkeywords)
- newfunc.func = func
- newfunc.args = args
- newfunc.keywords = keywords
- return newfunc
+import functools
+
+original_functools = functools
+py_functools = support.import_fresh_module('functools', blocked=['_functools'])
+c_functools = support.import_fresh_module('functools', fresh=['_functools'])
+
+class BaseTest(unittest.TestCase):
+
+ """Base class required for testing C and Py implementations."""
+
+ def setUp(self):
+
+ # The module must be explicitly set so that the proper
+ # interaction between the c module and the python module
+ # can be controlled.
+ self.partial = self.module.partial
+ super(BaseTest, self).setUp()
+
+class BaseTestC(BaseTest):
+ module = c_functools
+
+class BaseTestPy(BaseTest):
+ module = py_functools
+
+PythonPartial = py_functools.partial
def capture(*args, **kw):
"""capture all positional and keyword arguments"""
@@ -27,31 +40,32 @@
""" return the signature of a partial object """
return (part.func, part.args, part.keywords, part.__dict__)
-class TestPartial(unittest.TestCase):
+class TestPartial(object):
- thetype = functools.partial
+ partial = functools.partial
def test_basic_examples(self):
- p = self.thetype(capture, 1, 2, a=10, b=20)
+ p = self.partial(capture, 1, 2, a=10, b=20)
+ self.assertTrue(callable(p))
self.assertEqual(p(3, 4, b=30, c=40),
((1, 2, 3, 4), dict(a=10, b=30, c=40)))
- p = self.thetype(map, lambda x: x*10)
+ p = self.partial(map, lambda x: x*10)
self.assertEqual(list(p([1,2,3,4])), [10, 20, 30, 40])
def test_attributes(self):
- p = self.thetype(capture, 1, 2, a=10, b=20)
+ p = self.partial(capture, 1, 2, a=10, b=20)
# attributes should be readable
self.assertEqual(p.func, capture)
self.assertEqual(p.args, (1, 2))
self.assertEqual(p.keywords, dict(a=10, b=20))
# attributes should not be writable
- if not isinstance(self.thetype, type):
+ if not isinstance(self.partial, type):
return
self.assertRaises(AttributeError, setattr, p, 'func', map)
self.assertRaises(AttributeError, setattr, p, 'args', (1, 2))
self.assertRaises(AttributeError, setattr, p, 'keywords', dict(a=1, b=2))
- p = self.thetype(hex)
+ p = self.partial(hex)
try:
del p.__dict__
except TypeError:
@@ -60,9 +74,9 @@
self.fail('partial object allowed __dict__ to be deleted')
def test_argument_checking(self):
- self.assertRaises(TypeError, self.thetype) # need at least a func arg
+ self.assertRaises(TypeError, self.partial) # need at least a func arg
try:
- self.thetype(2)()
+ self.partial(2)()
except TypeError:
pass
else:
@@ -73,7 +87,7 @@
def func(a=10, b=20):
return a
d = {'a':3}
- p = self.thetype(func, a=5)
+ p = self.partial(func, a=5)
self.assertEqual(p(**d), 3)
self.assertEqual(d, {'a':3})
p(b=7)
@@ -82,20 +96,20 @@
def test_arg_combinations(self):
# exercise special code paths for zero args in either partial
# object or the caller
- p = self.thetype(capture)
+ p = self.partial(capture)
self.assertEqual(p(), ((), {}))
self.assertEqual(p(1,2), ((1,2), {}))
- p = self.thetype(capture, 1, 2)
+ p = self.partial(capture, 1, 2)
self.assertEqual(p(), ((1,2), {}))
self.assertEqual(p(3,4), ((1,2,3,4), {}))
def test_kw_combinations(self):
# exercise special code paths for no keyword args in
# either the partial object or the caller
- p = self.thetype(capture)
+ p = self.partial(capture)
self.assertEqual(p(), ((), {}))
self.assertEqual(p(a=1), ((), {'a':1}))
- p = self.thetype(capture, a=1)
+ p = self.partial(capture, a=1)
self.assertEqual(p(), ((), {'a':1}))
self.assertEqual(p(b=2), ((), {'a':1, 'b':2}))
# keyword args in the call override those in the partial object
@@ -104,7 +118,7 @@
def test_positional(self):
# make sure positional arguments are captured correctly
for args in [(), (0,), (0,1), (0,1,2), (0,1,2,3)]:
- p = self.thetype(capture, *args)
+ p = self.partial(capture, *args)
expected = args + ('x',)
got, empty = p('x')
self.assertTrue(expected == got and empty == {})
@@ -112,14 +126,14 @@
def test_keyword(self):
# make sure keyword arguments are captured correctly
for a in ['a', 0, None, 3.5]:
- p = self.thetype(capture, a=a)
+ p = self.partial(capture, a=a)
expected = {'a':a,'x':None}
empty, got = p(x=None)
self.assertTrue(expected == got and empty == ())
def test_no_side_effects(self):
# make sure there are no side effects that affect subsequent calls
- p = self.thetype(capture, 0, a=1)
+ p = self.partial(capture, 0, a=1)
args1, kw1 = p(1, b=2)
self.assertTrue(args1 == (0,1) and kw1 == {'a':1,'b':2})
args2, kw2 = p()
@@ -128,13 +142,13 @@
def test_error_propagation(self):
def f(x, y):
x / y
- self.assertRaises(ZeroDivisionError, self.thetype(f, 1, 0))
- self.assertRaises(ZeroDivisionError, self.thetype(f, 1), 0)
- self.assertRaises(ZeroDivisionError, self.thetype(f), 1, 0)
- self.assertRaises(ZeroDivisionError, self.thetype(f, y=0), 1)
+ self.assertRaises(ZeroDivisionError, self.partial(f, 1, 0))
+ self.assertRaises(ZeroDivisionError, self.partial(f, 1), 0)
+ self.assertRaises(ZeroDivisionError, self.partial(f), 1, 0)
+ self.assertRaises(ZeroDivisionError, self.partial(f, y=0), 1)
def test_weakref(self):
- f = self.thetype(int, base=16)
+ f = self.partial(int, base=16)
p = proxy(f)
self.assertEqual(f.func, p.func)
f = None
@@ -142,9 +156,9 @@
def test_with_bound_and_unbound_methods(self):
data = list(map(str, range(10)))
- join = self.thetype(str.join, '')
+ join = self.partial(str.join, '')
self.assertEqual(join(data), '0123456789')
- join = self.thetype(''.join)
+ join = self.partial(''.join)
self.assertEqual(join(data), '0123456789')
def test_repr(self):
@@ -152,49 +166,57 @@
args_repr = ', '.join(repr(a) for a in args)
kwargs = {'a': object(), 'b': object()}
kwargs_repr = ', '.join("%s=%r" % (k, v) for k, v in kwargs.items())
- if self.thetype is functools.partial:
+ if self.partial is functools.partial:
name = 'functools.partial'
else:
- name = self.thetype.__name__
+ name = self.partial.__name__
- f = self.thetype(capture)
+ f = self.partial(capture)
self.assertEqual('{}({!r})'.format(name, capture),
repr(f))
- f = self.thetype(capture, *args)
+ f = self.partial(capture, *args)
self.assertEqual('{}({!r}, {})'.format(name, capture, args_repr),
repr(f))
- f = self.thetype(capture, **kwargs)
+ f = self.partial(capture, **kwargs)
self.assertEqual('{}({!r}, {})'.format(name, capture, kwargs_repr),
repr(f))
- f = self.thetype(capture, *args, **kwargs)
+ f = self.partial(capture, *args, **kwargs)
self.assertEqual('{}({!r}, {}, {})'.format(name, capture, args_repr, kwargs_repr),
repr(f))
def test_pickle(self):
- f = self.thetype(signature, 'asdf', bar=True)
+ f = self.partial(signature, 'asdf', bar=True)
f.add_something_to__dict__ = True
f_copy = pickle.loads(pickle.dumps(f))
self.assertEqual(signature(f), signature(f_copy))
-class PartialSubclass(functools.partial):
+class TestPartialC(BaseTestC, TestPartial):
pass
-class TestPartialSubclass(TestPartial):
+class TestPartialPy(BaseTestPy, TestPartial):
- thetype = PartialSubclass
+ def test_pickle(self):
+ raise unittest.SkipTest("Python implementation of partial isn't picklable")
+
+ def test_repr(self):
+ raise unittest.SkipTest("Python implementation of partial uses own repr")
-class TestPythonPartial(TestPartial):
+class TestPartialCSubclass(BaseTestC, TestPartial):
- thetype = PythonPartial
+ class PartialSubclass(c_functools.partial):
+ pass
- # the python version hasn't a nice repr
- def test_repr(self): pass
+ partial = staticmethod(PartialSubclass)
- # the python version isn't picklable
- def test_pickle(self): pass
+class TestPartialPySubclass(TestPartialPy):
+
+ class PartialSubclass(c_functools.partial):
+ pass
+
+ partial = staticmethod(PartialSubclass)
class TestUpdateWrapper(unittest.TestCase):
@@ -320,7 +342,7 @@
self.assertEqual(wrapper.__qualname__, f.__qualname__)
self.assertEqual(wrapper.attr, 'This is also a test')
- @unittest.skipIf(not sys.flags.optimize <= 1,
+ @unittest.skipIf(sys.flags.optimize >= 2,
"Docstrings are omitted with -O2 and above")
def test_default_update_doc(self):
wrapper, _ = self._default_update()
@@ -441,24 +463,28 @@
d = {"one": 1, "two": 2, "three": 3}
self.assertEqual(self.func(add, d), "".join(d.keys()))
-class TestCmpToKey(unittest.TestCase):
+class TestCmpToKey(object):
def test_cmp_to_key(self):
def cmp1(x, y):
return (x > y) - (x < y)
- key = functools.cmp_to_key(cmp1)
+ key = self.cmp_to_key(cmp1)
self.assertEqual(key(3), key(3))
self.assertGreater(key(3), key(1))
+ self.assertGreaterEqual(key(3), key(3))
+
def cmp2(x, y):
return int(x) - int(y)
- key = functools.cmp_to_key(cmp2)
+ key = self.cmp_to_key(cmp2)
self.assertEqual(key(4.0), key('4'))
self.assertLess(key(2), key('35'))
+ self.assertLessEqual(key(2), key('35'))
+ self.assertNotEqual(key(2), key('35'))
def test_cmp_to_key_arguments(self):
def cmp1(x, y):
return (x > y) - (x < y)
- key = functools.cmp_to_key(mycmp=cmp1)
+ key = self.cmp_to_key(mycmp=cmp1)
self.assertEqual(key(obj=3), key(obj=3))
self.assertGreater(key(obj=3), key(obj=1))
with self.assertRaises((TypeError, AttributeError)):
@@ -466,10 +492,10 @@
with self.assertRaises((TypeError, AttributeError)):
1 < key(3) # lhs is not a K object
with self.assertRaises(TypeError):
- key = functools.cmp_to_key() # too few args
+ key = self.cmp_to_key() # too few args
with self.assertRaises(TypeError):
- key = functools.cmp_to_key(cmp1, None) # too many args
- key = functools.cmp_to_key(cmp1)
+ key = self.module.cmp_to_key(cmp1, None) # too many args
+ key = self.cmp_to_key(cmp1)
with self.assertRaises(TypeError):
key() # too few args
with self.assertRaises(TypeError):
@@ -478,7 +504,7 @@
def test_bad_cmp(self):
def cmp1(x, y):
raise ZeroDivisionError
- key = functools.cmp_to_key(cmp1)
+ key = self.cmp_to_key(cmp1)
with self.assertRaises(ZeroDivisionError):
key(3) > key(1)
@@ -493,13 +519,13 @@
def test_obj_field(self):
def cmp1(x, y):
return (x > y) - (x < y)
- key = functools.cmp_to_key(mycmp=cmp1)
+ key = self.cmp_to_key(mycmp=cmp1)
self.assertEqual(key(50).obj, 50)
def test_sort_int(self):
def mycmp(x, y):
return y - x
- self.assertEqual(sorted(range(5), key=functools.cmp_to_key(mycmp)),
+ self.assertEqual(sorted(range(5), key=self.cmp_to_key(mycmp)),
[4, 3, 2, 1, 0])
def test_sort_int_str(self):
@@ -507,18 +533,24 @@
x, y = int(x), int(y)
return (x > y) - (x < y)
values = [5, '3', 7, 2, '0', '1', 4, '10', 1]
- values = sorted(values, key=functools.cmp_to_key(mycmp))
+ values = sorted(values, key=self.cmp_to_key(mycmp))
self.assertEqual([int(value) for value in values],
[0, 1, 1, 2, 3, 4, 5, 7, 10])
def test_hash(self):
def mycmp(x, y):
return y - x
- key = functools.cmp_to_key(mycmp)
+ key = self.cmp_to_key(mycmp)
k = key(10)
self.assertRaises(TypeError, hash, k)
self.assertNotIsInstance(k, collections.Hashable)
+class TestCmpToKeyC(BaseTestC, TestCmpToKey):
+ cmp_to_key = c_functools.cmp_to_key
+
+class TestCmpToKeyPy(BaseTestPy, TestCmpToKey):
+ cmp_to_key = staticmethod(py_functools.cmp_to_key)
+
class TestTotalOrdering(unittest.TestCase):
def test_total_ordering_lt(self):
@@ -623,7 +655,7 @@
def test_lru(self):
def orig(x, y):
- return 3*x+y
+ return 3 * x + y
f = functools.lru_cache(maxsize=20)(orig)
hits, misses, maxsize, currsize = f.cache_info()
self.assertEqual(maxsize, 20)
@@ -728,7 +760,7 @@
# Verify that user_function exceptions get passed through without
# creating a hard-to-read chained exception.
# http://bugs.python.org/issue13177
- for maxsize in (None, 100):
+ for maxsize in (None, 128):
@functools.lru_cache(maxsize)
def func(i):
return 'abc'[i]
@@ -741,7 +773,7 @@
func(15)
def test_lru_with_types(self):
- for maxsize in (None, 100):
+ for maxsize in (None, 128):
@functools.lru_cache(maxsize=maxsize, typed=True)
def square(x):
return x * x
@@ -756,14 +788,46 @@
self.assertEqual(square.cache_info().hits, 4)
self.assertEqual(square.cache_info().misses, 4)
+ def test_lru_with_keyword_args(self):
+ @functools.lru_cache()
+ def fib(n):
+ if n < 2:
+ return n
+ return fib(n=n-1) + fib(n=n-2)
+ self.assertEqual(
+ [fib(n=number) for number in range(16)],
+ [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610]
+ )
+ self.assertEqual(fib.cache_info(),
+ functools._CacheInfo(hits=28, misses=16, maxsize=128, currsize=16))
+ fib.cache_clear()
+ self.assertEqual(fib.cache_info(),
+ functools._CacheInfo(hits=0, misses=0, maxsize=128, currsize=0))
+
+ def test_lru_with_keyword_args_maxsize_none(self):
+ @functools.lru_cache(maxsize=None)
+ def fib(n):
+ if n < 2:
+ return n
+ return fib(n=n-1) + fib(n=n-2)
+ self.assertEqual([fib(n=number) for number in range(16)],
+ [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610])
+ self.assertEqual(fib.cache_info(),
+ functools._CacheInfo(hits=28, misses=16, maxsize=None, currsize=16))
+ fib.cache_clear()
+ self.assertEqual(fib.cache_info(),
+ functools._CacheInfo(hits=0, misses=0, maxsize=None, currsize=0))
+
def test_main(verbose=None):
test_classes = (
- TestPartial,
- TestPartialSubclass,
- TestPythonPartial,
+ TestPartialC,
+ TestPartialPy,
+ TestPartialCSubclass,
+ TestPartialPySubclass,
TestUpdateWrapper,
TestTotalOrdering,
- TestCmpToKey,
+ TestCmpToKeyC,
+ TestCmpToKeyPy,
TestWraps,
TestReduce,
TestLRU,
diff --git a/Misc/ACKS b/Misc/ACKS
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1166,6 +1166,7 @@
Nicolas M. Thiéry
James Thomas
Robin Thomas
+Brian Thorne
Stephen Thorne
Jeremy Thurgood
Eric Tiedemann
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -124,6 +124,9 @@
Library
-------
+- Issue #12428: Add a pure Python implementation of functools.partial().
+ Patch by Brian Thorne.
+
- Issue #16140: The subprocess module no longer double closes its child
subprocess.PIPE parent file descriptors on child error prior to exec().
--
Repository URL: http://hg.python.org/cpython
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