PEP 372: OrderedDict()

This commit is contained in:
Raymond Hettinger 2009-03-02 21:24:57 +00:00
parent 57b46f5b0e
commit 2d32f63ec9
4 changed files with 300 additions and 6 deletions

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@ -1,5 +1,5 @@
__all__ = ['deque', 'defaultdict', 'namedtuple', 'UserDict', 'UserList',
'UserString', 'Counter']
'UserString', 'Counter', 'OrderedDict']
# For bootstrapping reasons, the collection ABCs are defined in _abcoll.py.
# They should however be considered an integral part of collections.py.
from _abcoll import *
@ -11,7 +11,81 @@ from operator import itemgetter as _itemgetter
from keyword import iskeyword as _iskeyword
import sys as _sys
import heapq as _heapq
from itertools import repeat as _repeat, chain as _chain, starmap as _starmap
from itertools import repeat as _repeat, chain as _chain, starmap as _starmap, \
zip_longest as _zip_longest
################################################################################
### OrderedDict
################################################################################
class OrderedDict(dict, MutableMapping):
def __init__(self, *args, **kwds):
if len(args) > 1:
raise TypeError('expected at most 1 arguments, got %d' % len(args))
if not hasattr(self, '_keys'):
self._keys = []
self.update(*args, **kwds)
def clear(self):
del self._keys[:]
dict.clear(self)
def __setitem__(self, key, value):
if key not in self:
self._keys.append(key)
dict.__setitem__(self, key, value)
def __delitem__(self, key):
dict.__delitem__(self, key)
self._keys.remove(key)
def __iter__(self):
return iter(self._keys)
def __reversed__(self):
return reversed(self._keys)
def popitem(self):
if not self:
raise KeyError('dictionary is empty')
key = self._keys.pop()
value = dict.pop(self, key)
return key, value
def __reduce__(self):
items = [[k, self[k]] for k in self]
inst_dict = vars(self).copy()
inst_dict.pop('_keys', None)
return (self.__class__, (items,), inst_dict)
setdefault = MutableMapping.setdefault
update = MutableMapping.update
pop = MutableMapping.pop
keys = MutableMapping.keys
values = MutableMapping.values
items = MutableMapping.items
def __repr__(self):
if not self:
return '%s()' % (self.__class__.__name__,)
return '%s(%r)' % (self.__class__.__name__, list(self.items()))
def copy(self):
return self.__class__(self)
@classmethod
def fromkeys(cls, iterable, value=None):
d = cls()
for key in iterable:
d[key] = value
return d
def __eq__(self, other):
if isinstance(other, OrderedDict):
return all(p==q for p, q in _zip_longest(self.items(), other.items()))
return dict.__eq__(self, other)
################################################################################

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@ -1,10 +1,12 @@
"""Unit tests for collections.py."""
import unittest, doctest
import inspect
from test import support
from collections import namedtuple, Counter, Mapping
from collections import namedtuple, Counter, OrderedDict
from test import mapping_tests
import pickle, copy
from random import randrange
from random import randrange, shuffle
import operator
from collections import Hashable, Iterable, Iterator
from collections import Sized, Container, Callable
@ -571,12 +573,201 @@ class TestCounter(unittest.TestCase):
set_result = setop(set(p.elements()), set(q.elements()))
self.assertEqual(counter_result, dict.fromkeys(set_result, 1))
class TestOrderedDict(unittest.TestCase):
def test_init(self):
with self.assertRaises(TypeError):
OrderedDict([('a', 1), ('b', 2)], None) # too many args
pairs = [('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5)]
self.assertEqual(sorted(OrderedDict(dict(pairs)).items()), pairs) # dict input
self.assertEqual(sorted(OrderedDict(**dict(pairs)).items()), pairs) # kwds input
self.assertEqual(list(OrderedDict(pairs).items()), pairs) # pairs input
self.assertEqual(list(OrderedDict([('a', 1), ('b', 2), ('c', 9), ('d', 4)],
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'])
# Make sure that direct calls to __init__ do not clear previous contents
d = OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 44), ('e', 55)])
d.__init__([('e', 5), ('f', 6)], g=7, d=4)
self.assertEqual(list(d.items()),
[('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5), ('f', 6), ('g', 7)])
def test_update(self):
with self.assertRaises(TypeError):
OrderedDict().update([('a', 1), ('b', 2)], None) # too many args
pairs = [('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5)]
od = OrderedDict()
od.update(dict(pairs))
self.assertEqual(sorted(od.items()), pairs) # dict input
od = OrderedDict()
od.update(**dict(pairs))
self.assertEqual(sorted(od.items()), pairs) # kwds input
od = OrderedDict()
od.update(pairs)
self.assertEqual(list(od.items()), pairs) # pairs input
od = OrderedDict()
od.update([('a', 1), ('b', 2), ('c', 9), ('d', 4)], c=3, e=5)
self.assertEqual(list(od.items()), pairs) # mixed input
# Make sure that direct calls to update do not clear previous contents
# add that updates items are not moved to the end
d = OrderedDict([('a', 1), ('b', 2), ('c', 3), ('d', 44), ('e', 55)])
d.update([('e', 5), ('f', 6)], g=7, d=4)
self.assertEqual(list(d.items()),
[('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5), ('f', 6), ('g', 7)])
def test_clear(self):
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
shuffle(pairs)
od = OrderedDict(pairs)
self.assertEqual(len(od), len(pairs))
od.clear()
self.assertEqual(len(od), 0)
def test_delitem(self):
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
od = OrderedDict(pairs)
del od['a']
self.assert_('a' not in od)
with self.assertRaises(KeyError):
del od['a']
self.assertEqual(list(od.items()), pairs[:2] + pairs[3:])
def test_setitem(self):
od = OrderedDict([('d', 1), ('b', 2), ('c', 3), ('a', 4), ('e', 5)])
od['c'] = 10 # existing element
od['f'] = 20 # new element
self.assertEqual(list(od.items()),
[('d', 1), ('b', 2), ('c', 10), ('a', 4), ('e', 5), ('f', 20)])
def test_iterators(self):
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
shuffle(pairs)
od = OrderedDict(pairs)
self.assertEqual(list(od), [t[0] for t in pairs])
self.assertEqual(list(od.keys()), [t[0] for t in pairs])
self.assertEqual(list(od.values()), [t[1] for t in pairs])
self.assertEqual(list(od.items()), pairs)
self.assertEqual(list(reversed(od)),
[t[0] for t in reversed(pairs)])
def test_popitem(self):
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
shuffle(pairs)
od = OrderedDict(pairs)
while pairs:
self.assertEqual(od.popitem(), pairs.pop())
with self.assertRaises(KeyError):
od.popitem()
self.assertEqual(len(od), 0)
def test_pop(self):
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
shuffle(pairs)
od = OrderedDict(pairs)
shuffle(pairs)
while pairs:
k, v = pairs.pop()
self.assertEqual(od.pop(k), v)
with self.assertRaises(KeyError):
od.pop('xyz')
self.assertEqual(len(od), 0)
self.assertEqual(od.pop(k, 12345), 12345)
def test_equality(self):
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
shuffle(pairs)
od1 = OrderedDict(pairs)
od2 = OrderedDict(pairs)
self.assertEqual(od1, od2) # same order implies equality
pairs = pairs[2:] + pairs[:2]
od2 = OrderedDict(pairs)
self.assertNotEqual(od1, od2) # different order implies inequality
# comparison to regular dict is not order sensitive
self.assertEqual(od1, dict(od2))
self.assertEqual(dict(od2), od1)
# different length implied inequality
self.assertNotEqual(od1, OrderedDict(pairs[:-1]))
def test_copying(self):
# Check that ordered dicts are copyable, deepcopyable, picklable,
# and have a repr/eval round-trip
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
od = OrderedDict(pairs)
update_test = OrderedDict()
update_test.update(od)
for i, dup in enumerate([
od.copy(),
copy.copy(od),
copy.deepcopy(od),
pickle.loads(pickle.dumps(od, 0)),
pickle.loads(pickle.dumps(od, 1)),
pickle.loads(pickle.dumps(od, 2)),
pickle.loads(pickle.dumps(od, 3)),
pickle.loads(pickle.dumps(od, -1)),
eval(repr(od)),
update_test,
OrderedDict(od),
]):
self.assert_(dup is not od)
self.assertEquals(dup, od)
self.assertEquals(list(dup.items()), list(od.items()))
self.assertEquals(len(dup), len(od))
self.assertEquals(type(dup), type(od))
def test_repr(self):
od = OrderedDict([('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)])
self.assertEqual(repr(od),
"OrderedDict([('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)])")
self.assertEqual(eval(repr(od)), od)
self.assertEqual(repr(OrderedDict()), "OrderedDict()")
def test_setdefault(self):
pairs = [('c', 1), ('b', 2), ('a', 3), ('d', 4), ('e', 5), ('f', 6)]
shuffle(pairs)
od = OrderedDict(pairs)
pair_order = list(od.items())
self.assertEqual(od.setdefault('a', 10), 3)
# make sure order didn't change
self.assertEqual(list(od.items()), pair_order)
self.assertEqual(od.setdefault('x', 10), 10)
# make sure 'x' is added to the end
self.assertEqual(list(od.items())[-1], ('x', 10))
def test_reinsert(self):
# Given insert a, insert b, delete a, re-insert a,
# verify that a is now later than b.
od = OrderedDict()
od['a'] = 1
od['b'] = 2
del od['a']
od['a'] = 1
self.assertEqual(list(od.items()), [('b', 2), ('a', 1)])
class GeneralMappingTests(mapping_tests.BasicTestMappingProtocol):
type2test = OrderedDict
class MyOrderedDict(OrderedDict):
pass
class SubclassMappingTests(mapping_tests.BasicTestMappingProtocol):
type2test = MyOrderedDict
import doctest, collections
def test_main(verbose=None):
NamedTupleDocs = doctest.DocTestSuite(module=collections)
test_classes = [TestNamedTuple, NamedTupleDocs, TestOneTrickPonyABCs,
TestCollectionABCs, TestCounter]
TestCollectionABCs, TestCounter,
TestOrderedDict, GeneralMappingTests, SubclassMappingTests]
support.run_unittest(*test_classes)
support.run_doctest(collections, verbose)