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))
def test_basics(self):
c = Counter('abcaba')
self.assertEqual(c, Counter({'a':3 , 'b': 2, 'c': 1}))
self.assertEqual(c, Counter(a=3, b=2, c=1))
self.assertIsInstance(c, dict)
self.assertIsInstance(c, Mapping)
self.assertTrue(issubclass(Counter, dict))
self.assertTrue(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.__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({'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
del c['c'] # make sure that del doesn't raise KeyError
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.assertNotIn('f', c)
for i in range(3):
elem, cnt = c.popitem()
self.assertNotIn(elem, c)
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.update(c=1)
c.update(Counter('a' * 50 + 'b' * 30))
c.update() # test case with no args
c.__init__('a' * 500 + 'b' * 300)
c.__init__('cdc')
c.__init__()
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_inplace_operations(self):
elements = 'abcd'
for i in range(1000):
# test random pairs of multisets
p = Counter(dict((elem, randrange(-2, 4)) for elem in elements))
p.update(e=1, f=-1, g=0)
q = Counter(dict((elem, randrange(-2, 4)) for elem in elements))
q.update(h=1, i=-1, j=0)
for inplace_op, regular_op in [
(Counter.__iadd__, Counter.__add__),
(Counter.__isub__, Counter.__sub__),
(Counter.__ior__, Counter.__or__),
(Counter.__iand__, Counter.__and__),
]:
c = p.copy()
c_id = id(c)
regular_result = regular_op(c, q)
inplace_result = inplace_op(c, q)
self.assertEqual(inplace_result, regular_result)
self.assertEqual(id(inplace_result), c_id)
def test_subtract(self):
c = Counter(a=-5, b=0, c=5, d=10, e=15,g=40)
c.subtract(a=1, b=2, c=-3, d=10, e=20, f=30, h=-50)
self.assertEqual(c, Counter(a=-6, b=-2, c=8, d=0, e=-5, f=-30, g=40, h=50))
c = Counter(a=-5, b=0, c=5, d=10, e=15,g=40)
c.subtract(Counter(a=1, b=2, c=-3, d=10, e=20, f=30, h=-50))
self.assertEqual(c, Counter(a=-6, b=-2, c=8, d=0, e=-5, f=-30, g=40, h=50))
c = Counter('aaabbcd')
c.subtract('aaaabbcce')
self.assertEqual(c, Counter(a=-1, b=0, c=-1, d=1, e=-1))
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)),
eval(repr(words)),
update_test,
Counter(words),
]):
msg = (i, dup, words)
self.assertTrue(dup is not words)
self.assertEqual(dup, words)
self.assertEqual(len(dup), len(words))
self.assertEqual(type(dup), type(words))
def test_multiset_operations(self):
# Verify that adding a zero counter will strip zeros and negatives
c = Counter(a=10, b=-2, c=0) + Counter()
self.assertEqual(dict(c), dict(a=10))
elements = 'abcd'
for i in range(1000):
# test random pairs of multisets
p = Counter(dict((elem, randrange(-2, 4)) for elem in elements))
p.update(e=1, f=-1, g=0)
q = Counter(dict((elem, randrange(-2, 4)) for elem in elements))
q.update(h=1, i=-1, j=0)
for counterop, numberop in [
(Counter.__add__, lambda x, y: max(0, x + y)),
(Counter.__sub__, lambda x, y: max(0, x - y)),
(Counter.__or__, lambda x, y: max(0, x, y)),
(Counter.__and__, lambda x, y: max(0, min(x, y))),
]:
result = counterop(p, q)
for x in elements:
self.assertEqual(numberop(p[x], q[x]), result[x],
(counterop, x, p, q))
# verify that results exclude non-positive counts
self.assertTrue(x > 0 for x in result.values())
elements = 'abcdef'
for i in range(100):
# verify that random multisets with no repeats are exactly like sets
p = Counter(dict((elem, randrange(0, 2)) for elem in elements))
q = Counter(dict((elem, randrange(0, 2)) for elem in elements))
for counterop, setop in [
(Counter.__sub__, set.__sub__),
(Counter.__or__, set.__or__),
(Counter.__and__, set.__and__),
]:
counter_result = counterop(p, q)
set_result = setop(set(p.elements()), set(q.elements()))
self.assertEqual(counter_result, dict.fromkeys(set_result, 1))
def test_repr_nonsortable(self):
c = Counter(a=2, b=None)
r = repr(c)
self.assertIn("'a': 2", r)
self.assertIn("'b': None", r)
def test_unary(self):
c = Counter(a=-5, b=0, c=5, d=10, e=15, g=40)
self.assertEqual(dict(+c), dict(c=5, d=10, e=15, g=40))
self.assertEqual(dict(-c), dict(a=5))
def test_invariant_for_the_in_operator(self):
c = Counter(a=10, b=-2, c=0)
for elem in c:
self.assertTrue(elem in c)
self.assertIn(elem, c)
def get(self, key, default):
self.called = True
return Counter.get(self, key, default)
def __init__(self, *args, **kwds):
self.called = False
Counter.__init__(self, *args, **kwds)
def __setitem__(self, key, value):
self.called = True
Counter.__setitem__(self, key, value)
def get(self, key, default):
self.called = True
return Counter.get(self, key, default)
def __init__(self, *args, **kwds):
self.called = False
Counter.__init__(self, *args, **kwds)
def __setitem__(self, key, value):
self.called = True
Counter.__setitem__(self, key, value)