Issue #22609: Constructors and update methods of mapping classes in the
collections module now accept the self keyword argument.
diff --git a/Lib/_abcoll.py b/Lib/_abcoll.py
index 3d567e3..0385627 100644
--- a/Lib/_abcoll.py
+++ b/Lib/_abcoll.py
@@ -548,23 +548,25 @@
If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v
In either case, this is followed by: for k, v in F.items(): D[k] = v
'''
- if len(args) > 2:
- raise TypeError("update() takes at most 2 positional "
- "arguments ({} given)".format(len(args)))
- elif not args:
- raise TypeError("update() takes at least 1 argument (0 given)")
+ if not args:
+ raise TypeError("descriptor 'update' of 'MutableMapping' object "
+ "needs an argument")
self = args[0]
- other = args[1] if len(args) >= 2 else ()
-
- if isinstance(other, Mapping):
- for key in other:
- self[key] = other[key]
- elif hasattr(other, "keys"):
- for key in other.keys():
- self[key] = other[key]
- else:
- for key, value in other:
- self[key] = value
+ args = args[1:]
+ if len(args) > 1:
+ raise TypeError('update expected at most 1 arguments, got %d' %
+ len(args))
+ if args:
+ other = args[0]
+ if isinstance(other, Mapping):
+ for key in other:
+ self[key] = other[key]
+ elif hasattr(other, "keys"):
+ for key in other.keys():
+ self[key] = other[key]
+ else:
+ for key, value in other:
+ self[key] = value
for key, value in kwds.items():
self[key] = value
diff --git a/Lib/collections.py b/Lib/collections.py
index 8831f0b..1dcd233 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -35,12 +35,17 @@
# The sentinel element never gets deleted (this simplifies the algorithm).
# Each link is stored as a list of length three: [PREV, NEXT, KEY].
- def __init__(self, *args, **kwds):
+ def __init__(*args, **kwds):
'''Initialize an ordered dictionary. The signature is the same as
regular dictionaries, but keyword arguments are not recommended because
their insertion order is arbitrary.
'''
+ if not args:
+ raise TypeError("descriptor '__init__' of 'OrderedDict' object "
+ "needs an argument")
+ self = args[0]
+ args = args[1:]
if len(args) > 1:
raise TypeError('expected at most 1 arguments, got %d' % len(args))
try:
@@ -438,7 +443,7 @@
# http://code.activestate.com/recipes/259174/
# Knuth, TAOCP Vol. II section 4.6.3
- def __init__(self, iterable=None, **kwds):
+ def __init__(*args, **kwds):
'''Create a new, empty Counter object. And if given, count elements
from an input iterable. Or, initialize the count from another mapping
of elements to their counts.
@@ -449,8 +454,15 @@
>>> c = Counter(a=4, b=2) # a new counter from keyword args
'''
+ if not args:
+ raise TypeError("descriptor '__init__' of 'Counter' object "
+ "needs an argument")
+ self = args[0]
+ args = args[1:]
+ if len(args) > 1:
+ raise TypeError('expected at most 1 arguments, got %d' % len(args))
super(Counter, self).__init__()
- self.update(iterable, **kwds)
+ self.update(*args, **kwds)
def __missing__(self, key):
'The count of elements not in the Counter is zero.'
@@ -501,7 +513,7 @@
raise NotImplementedError(
'Counter.fromkeys() is undefined. Use Counter(iterable) instead.')
- def update(self, iterable=None, **kwds):
+ def update(*args, **kwds):
'''Like dict.update() but add counts instead of replacing them.
Source can be an iterable, a dictionary, or another Counter instance.
@@ -521,6 +533,14 @@
# contexts. Instead, we implement straight-addition. Both the inputs
# and outputs are allowed to contain zero and negative counts.
+ if not args:
+ raise TypeError("descriptor 'update' of 'Counter' object "
+ "needs an argument")
+ self = args[0]
+ args = args[1:]
+ if len(args) > 1:
+ raise TypeError('expected at most 1 arguments, got %d' % len(args))
+ iterable = args[0] if args else None
if iterable is not None:
if isinstance(iterable, Mapping):
if self:
@@ -536,7 +556,7 @@
if kwds:
self.update(kwds)
- def subtract(self, iterable=None, **kwds):
+ def subtract(*args, **kwds):
'''Like dict.update() but subtracts counts instead of replacing them.
Counts can be reduced below zero. Both the inputs and outputs are
allowed to contain zero and negative counts.
@@ -552,6 +572,14 @@
-1
'''
+ if not args:
+ raise TypeError("descriptor 'subtract' of 'Counter' object "
+ "needs an argument")
+ self = args[0]
+ args = args[1:]
+ if len(args) > 1:
+ raise TypeError('expected at most 1 arguments, got %d' % len(args))
+ iterable = args[0] if args else None
if iterable is not None:
self_get = self.get
if isinstance(iterable, Mapping):
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index 20e0667..cd27227 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -905,6 +905,28 @@
self.assertEqual(c.setdefault('e', 5), 5)
self.assertEqual(c['e'], 5)
+ def test_init(self):
+ self.assertEqual(list(Counter(self=42).items()), [('self', 42)])
+ self.assertEqual(list(Counter(iterable=42).items()), [('iterable', 42)])
+ self.assertEqual(list(Counter(iterable=None).items()), [('iterable', None)])
+ self.assertRaises(TypeError, Counter, 42)
+ self.assertRaises(TypeError, Counter, (), ())
+ self.assertRaises(TypeError, Counter.__init__)
+
+ def test_update(self):
+ c = Counter()
+ c.update(self=42)
+ self.assertEqual(list(c.items()), [('self', 42)])
+ c = Counter()
+ c.update(iterable=42)
+ self.assertEqual(list(c.items()), [('iterable', 42)])
+ c = Counter()
+ c.update(iterable=None)
+ self.assertEqual(list(c.items()), [('iterable', None)])
+ self.assertRaises(TypeError, Counter().update, 42)
+ self.assertRaises(TypeError, Counter().update, {}, {})
+ self.assertRaises(TypeError, Counter.update)
+
def test_copying(self):
# Check that counters are copyable, deepcopyable, picklable, and
#have a repr/eval round-trip
@@ -1006,6 +1028,16 @@
c.subtract('aaaabbcce')
self.assertEqual(c, Counter(a=-1, b=0, c=-1, d=1, e=-1))
+ c = Counter()
+ c.subtract(self=42)
+ self.assertEqual(list(c.items()), [('self', -42)])
+ c = Counter()
+ c.subtract(iterable=42)
+ self.assertEqual(list(c.items()), [('iterable', -42)])
+ self.assertRaises(TypeError, Counter().subtract, 42)
+ self.assertRaises(TypeError, Counter().subtract, {}, {})
+ self.assertRaises(TypeError, Counter.subtract)
+
class TestOrderedDict(unittest.TestCase):
def test_init(self):
@@ -1019,8 +1051,11 @@
c=3, e=5).items()), pairs) # mixed input
# make sure no positional args conflict with possible kwdargs
- self.assertEqual(inspect.getargspec(OrderedDict.__dict__['__init__']).args,
- ['self'])
+ self.assertEqual(list(OrderedDict(self=42).items()), [('self', 42)])
+ self.assertEqual(list(OrderedDict(other=42).items()), [('other', 42)])
+ self.assertRaises(TypeError, OrderedDict, 42)
+ self.assertRaises(TypeError, OrderedDict, (), ())
+ self.assertRaises(TypeError, OrderedDict.__init__)
# Make sure that direct calls to __init__ do not clear previous contents
d = OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 44), ('e', 55)])
@@ -1065,6 +1100,10 @@
self.assertEqual(list(d.items()),
[('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5), ('f', 6), ('g', 7)])
+ self.assertRaises(TypeError, OrderedDict().update, 42)
+ self.assertRaises(TypeError, OrderedDict().update, (), ())
+ self.assertRaises(TypeError, OrderedDict.update)
+
def test_abc(self):
self.assertIsInstance(OrderedDict(), MutableMapping)
self.assertTrue(issubclass(OrderedDict, MutableMapping))