Issue 1696199: Add collections.Counter().
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index 7dffd73..00882e2 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -1,6 +1,6 @@
import unittest, doctest
from test import test_support
-from collections import namedtuple
+from collections import namedtuple, Counter, Mapping
import pickle, cPickle, copy
from collections import Hashable, Iterable, Iterator
from collections import Sized, Container, Callable
@@ -346,11 +346,107 @@
self.failUnless(issubclass(sample, MutableSequence))
self.failIf(issubclass(basestring, MutableSequence))
+class TestCounter(unittest.TestCase):
+
+ def test_basics(self):
+ c = Counter('abcaba')
+ self.assert_(isinstance(c, dict))
+ self.assert_(isinstance(c, Mapping))
+ self.assert_(issubclass(Counter, dict))
+ self.assert_(issubclass(Counter, Mapping))
+ self.assertEqual(len(c), 3)
+ self.assertEqual(sum(c.values()), 6)
+ self.assertEqual(sorted(c.values()), [1, 2, 3])
+ self.assertEqual(sorted(c.keys()), ['a', 'b', 'c'])
+ self.assertEqual(sorted(c), ['a', 'b', 'c'])
+ self.assertEqual(sorted(c.items()),
+ [('a', 3), ('b', 2), ('c', 1)])
+ self.assertEqual(c['b'], 2)
+ self.assertEqual(c['z'], 0)
+ self.assertEqual(c.has_key('c'), True)
+ self.assertEqual(c.has_key('z'), False)
+ self.assertEqual(c.__contains__('c'), True)
+ self.assertEqual(c.__contains__('z'), False)
+ self.assertEqual(c.get('b', 10), 2)
+ self.assertEqual(c.get('z', 10), 10)
+ self.assertEqual(c, dict(a=3, b=2, c=1))
+ self.assertEqual(repr(c),
+ "Counter(items=[('a', 3), ('b', 2), ('c', 1)])")
+ self.assertEqual(c.most_common(), [('a', 3), ('b', 2), ('c', 1)])
+ for i in range(5):
+ self.assertEqual(c.most_common(i),
+ [('a', 3), ('b', 2), ('c', 1)][:i])
+ self.assertEqual(''.join(sorted(c.elements())), 'aaabbc')
+ c['a'] += 1 # increment an existing value
+ c['b'] -= 2 # sub existing value to zero
+ del c['c'] # remove an entry
+ c['d'] -= 2 # sub from a missing value
+ c['e'] = -5 # directly assign a missing value
+ c['f'] += 4 # add to a missing value
+ self.assertEqual(c, dict(a=4, b=0, d=-2, e=-5, f=4))
+ self.assertEqual(''.join(sorted(c.elements())), 'aaaaffff')
+ self.assertEqual(c.pop('f'), 4)
+ self.assertEqual('f' in c, False)
+ for i in range(3):
+ elem, cnt = c.popitem()
+ self.assertEqual(elem in c, False)
+ c.clear()
+ self.assertEqual(c, {})
+ self.assertEqual(repr(c), 'Counter()')
+ self.assertRaises(NotImplementedError, Counter.fromkeys, 'abc')
+ self.assertRaises(TypeError, hash, c)
+ c.update(dict(a=5, b=3, c=1))
+ c.update(Counter(items=[('a', 50), ('b', 30)]))
+ c.__init__(items=[('a', 500), ('b', 300)])
+ c.__init__('cdc')
+ self.assertEqual(c, dict(a=555, b=333, c=3, d=1))
+ self.assertEqual(c.setdefault('d', 5), 1)
+ self.assertEqual(c['d'], 1)
+ self.assertEqual(c.setdefault('e', 5), 5)
+ self.assertEqual(c['e'], 5)
+
+ def test_copying(self):
+ # Check that counters are copyable, deepcopyable, picklable, and
+ #have a repr/eval round-trip
+ words = Counter('which witch had which witches wrist watch'.split())
+ update_test = Counter()
+ update_test.update(words)
+ for i, dup in enumerate([
+ words.copy(),
+ copy.copy(words),
+ copy.deepcopy(words),
+ pickle.loads(pickle.dumps(words, 0)),
+ pickle.loads(pickle.dumps(words, 1)),
+ pickle.loads(pickle.dumps(words, 2)),
+ pickle.loads(pickle.dumps(words, -1)),
+ cPickle.loads(cPickle.dumps(words, 0)),
+ cPickle.loads(cPickle.dumps(words, 1)),
+ cPickle.loads(cPickle.dumps(words, 2)),
+ cPickle.loads(cPickle.dumps(words, -1)),
+ eval(repr(words)),
+ update_test,
+ ]):
+ msg = (i, dup, words)
+ self.assert_(dup is not words)
+ self.assertEquals(dup, words)
+ self.assertEquals(len(dup), len(words))
+ self.assertEquals(type(dup), type(words))
+
+ def test_conversions(self):
+ # Convert to: set, list, dict
+ s = 'she sells sea shells by the sea shore'
+ self.assertEqual(sorted(Counter(s).elements()), sorted(s))
+ self.assertEqual(sorted(Counter(s)), sorted(set(s)))
+ self.assertEqual(dict(Counter(s)), dict(Counter(s).items()))
+ self.assertEqual(set(Counter(s)), set(s))
+
+
import doctest, collections
def test_main(verbose=None):
NamedTupleDocs = doctest.DocTestSuite(module=collections)
- test_classes = [TestNamedTuple, NamedTupleDocs, TestOneTrickPonyABCs, TestCollectionABCs]
+ test_classes = [TestNamedTuple, NamedTupleDocs, TestOneTrickPonyABCs,
+ TestCollectionABCs, TestCounter]
test_support.run_unittest(*test_classes)
test_support.run_doctest(collections, verbose)