self.assertEqual(r1, r2)
self.assertEqual(e1, e2)
+
+ def test_groupby_recipe(self):
+
+ # Begin groupby() recipe #######################################
+
+ def groupby(iterable, key=None):
+ # [k for k, g in groupby('AAAABBBCCDAABBB')] → A B C D A B
+ # [list(g) for k, g in groupby('AAAABBBCCD')] → AAAA BBB CC D
+
+ keyfunc = (lambda x: x) if key is None else key
+ iterator = iter(iterable)
+ exhausted = False
+
+ def _grouper(target_key):
+ nonlocal curr_value, curr_key, exhausted
+ yield curr_value
+ for curr_value in iterator:
+ curr_key = keyfunc(curr_value)
+ if curr_key != target_key:
+ return
+ yield curr_value
+ exhausted = True
+
+ try:
+ curr_value = next(iterator)
+ except StopIteration:
+ return
+ curr_key = keyfunc(curr_value)
+
+ while not exhausted:
+ target_key = curr_key
+ curr_group = _grouper(target_key)
+ yield curr_key, curr_group
+ if curr_key == target_key:
+ for _ in curr_group:
+ pass
+
+ # End groupby() recipe #########################################
+
+ # Check whether it accepts arguments correctly
+ self.assertEqual([], list(groupby([])))
+ self.assertEqual([], list(groupby([], key=id)))
+ self.assertRaises(TypeError, list, groupby('abc', []))
+ if False:
+ # Test not applicable to the recipe
+ self.assertRaises(TypeError, list, groupby('abc', None))
+ self.assertRaises(TypeError, groupby, 'abc', lambda x:x, 10)
+
+ # Check normal input
+ s = [(0, 10, 20), (0, 11,21), (0,12,21), (1,13,21), (1,14,22),
+ (2,15,22), (3,16,23), (3,17,23)]
+ dup = []
+ for k, g in groupby(s, lambda r:r[0]):
+ for elem in g:
+ self.assertEqual(k, elem[0])
+ dup.append(elem)
+ self.assertEqual(s, dup)
+
+ # Check nested case
+ dup = []
+ for k, g in groupby(s, testR):
+ for ik, ig in groupby(g, testR2):
+ for elem in ig:
+ self.assertEqual(k, elem[0])
+ self.assertEqual(ik, elem[2])
+ dup.append(elem)
+ self.assertEqual(s, dup)
+
+ # Check case where inner iterator is not used
+ keys = [k for k, g in groupby(s, testR)]
+ expectedkeys = set([r[0] for r in s])
+ self.assertEqual(set(keys), expectedkeys)
+ self.assertEqual(len(keys), len(expectedkeys))
+
+ # Check case where inner iterator is used after advancing the groupby
+ # iterator
+ s = list(zip('AABBBAAAA', range(9)))
+ it = groupby(s, testR)
+ _, g1 = next(it)
+ _, g2 = next(it)
+ _, g3 = next(it)
+ self.assertEqual(list(g1), [])
+ self.assertEqual(list(g2), [])
+ self.assertEqual(next(g3), ('A', 5))
+ list(it) # exhaust the groupby iterator
+ self.assertEqual(list(g3), [])
+
+ # Exercise pipes and filters style
+ s = 'abracadabra'
+ # sort s | uniq
+ r = [k for k, g in groupby(sorted(s))]
+ self.assertEqual(r, ['a', 'b', 'c', 'd', 'r'])
+ # sort s | uniq -d
+ r = [k for k, g in groupby(sorted(s)) if list(islice(g,1,2))]
+ self.assertEqual(r, ['a', 'b', 'r'])
+ # sort s | uniq -c
+ r = [(len(list(g)), k) for k, g in groupby(sorted(s))]
+ self.assertEqual(r, [(5, 'a'), (2, 'b'), (1, 'c'), (1, 'd'), (2, 'r')])
+ # sort s | uniq -c | sort -rn | head -3
+ r = sorted([(len(list(g)) , k) for k, g in groupby(sorted(s))], reverse=True)[:3]
+ self.assertEqual(r, [(5, 'a'), (2, 'r'), (2, 'b')])
+
+ # iter.__next__ failure
+ class ExpectedError(Exception):
+ pass
+ def delayed_raise(n=0):
+ for i in range(n):
+ yield 'yo'
+ raise ExpectedError
+ def gulp(iterable, keyp=None, func=list):
+ return [func(g) for k, g in groupby(iterable, keyp)]
+
+ # iter.__next__ failure on outer object
+ self.assertRaises(ExpectedError, gulp, delayed_raise(0))
+ # iter.__next__ failure on inner object
+ self.assertRaises(ExpectedError, gulp, delayed_raise(1))
+
+ # __eq__ failure
+ class DummyCmp:
+ def __eq__(self, dst):
+ raise ExpectedError
+ s = [DummyCmp(), DummyCmp(), None]
+
+ # __eq__ failure on outer object
+ self.assertRaises(ExpectedError, gulp, s, func=id)
+ # __eq__ failure on inner object
+ self.assertRaises(ExpectedError, gulp, s)
+
+ # keyfunc failure
+ def keyfunc(obj):
+ if keyfunc.skip > 0:
+ keyfunc.skip -= 1
+ return obj
+ else:
+ raise ExpectedError
+
+ # keyfunc failure on outer object
+ keyfunc.skip = 0
+ self.assertRaises(ExpectedError, gulp, [None], keyfunc)
+ keyfunc.skip = 1
+ self.assertRaises(ExpectedError, gulp, [None, None], keyfunc)
+
+
@staticmethod
def islice(iterable, *args):
+ # islice('ABCDEFG', 2) → A B
+ # islice('ABCDEFG', 2, 4) → C D
+ # islice('ABCDEFG', 2, None) → C D E F G
+ # islice('ABCDEFG', 0, None, 2) → A C E G
+
s = slice(*args)
- start, stop, step = s.start or 0, s.stop or sys.maxsize, s.step or 1
- it = iter(range(start, stop, step))
- try:
- nexti = next(it)
- except StopIteration:
- # Consume *iterable* up to the *start* position.
- for i, element in zip(range(start), iterable):
- pass
- return
- try:
- for i, element in enumerate(iterable):
- if i == nexti:
- yield element
- nexti = next(it)
- except StopIteration:
- # Consume to *stop*.
- for i, element in zip(range(i + 1, stop), iterable):
- pass
+ start = 0 if s.start is None else s.start
+ stop = s.stop
+ step = 1 if s.step is None else s.step
+ if start < 0 or (stop is not None and stop < 0) or step <= 0:
+ raise ValueError
+
+ indices = count() if stop is None else range(max(start, stop))
+ next_i = start
+ for i, element in zip(indices, iterable):
+ if i == next_i:
+ yield element
+ next_i += step
def test_islice_recipe(self):
self.assertEqual(list(self.islice('ABCDEFG', 2)), list('AB'))
self.assertEqual(next(c), 3)
+ def test_tee_recipe(self):
+
+ # Begin tee() recipe ###########################################
+
+ def tee(iterable, n=2):
+ iterator = iter(iterable)
+ shared_link = [None, None]
+ return tuple(_tee(iterator, shared_link) for _ in range(n))
+
+ def _tee(iterator, link):
+ try:
+ while True:
+ if link[1] is None:
+ link[0] = next(iterator)
+ link[1] = [None, None]
+ value, link = link
+ yield value
+ except StopIteration:
+ return
+
+ # End tee() recipe #############################################
+
+ n = 200
+
+ a, b = tee([]) # test empty iterator
+ self.assertEqual(list(a), [])
+ self.assertEqual(list(b), [])
+
+ a, b = tee(irange(n)) # test 100% interleaved
+ self.assertEqual(lzip(a,b), lzip(range(n), range(n)))
+
+ a, b = tee(irange(n)) # test 0% interleaved
+ self.assertEqual(list(a), list(range(n)))
+ self.assertEqual(list(b), list(range(n)))
+
+ a, b = tee(irange(n)) # test dealloc of leading iterator
+ for i in range(100):
+ self.assertEqual(next(a), i)
+ del a
+ self.assertEqual(list(b), list(range(n)))
+
+ a, b = tee(irange(n)) # test dealloc of trailing iterator
+ for i in range(100):
+ self.assertEqual(next(a), i)
+ del b
+ self.assertEqual(list(a), list(range(100, n)))
+
+ for j in range(5): # test randomly interleaved
+ order = [0]*n + [1]*n
+ random.shuffle(order)
+ lists = ([], [])
+ its = tee(irange(n))
+ for i in order:
+ value = next(its[i])
+ lists[i].append(value)
+ self.assertEqual(lists[0], list(range(n)))
+ self.assertEqual(lists[1], list(range(n)))
+
+ # test argument format checking
+ self.assertRaises(TypeError, tee)
+ self.assertRaises(TypeError, tee, 3)
+ self.assertRaises(TypeError, tee, [1,2], 'x')
+ self.assertRaises(TypeError, tee, [1,2], 3, 'x')
+
+ # Tests not applicable to the tee() recipe
+ if False:
+ # tee object should be instantiable
+ a, b = tee('abc')
+ c = type(a)('def')
+ self.assertEqual(list(c), list('def'))
+
+ # test long-lagged and multi-way split
+ a, b, c = tee(range(2000), 3)
+ for i in range(100):
+ self.assertEqual(next(a), i)
+ self.assertEqual(list(b), list(range(2000)))
+ self.assertEqual([next(c), next(c)], list(range(2)))
+ self.assertEqual(list(a), list(range(100,2000)))
+ self.assertEqual(list(c), list(range(2,2000)))
+
+ # Tests not applicable to the tee() recipe
+ if False:
+ # test invalid values of n
+ self.assertRaises(TypeError, tee, 'abc', 'invalid')
+ self.assertRaises(ValueError, tee, [], -1)
+
+ for n in range(5):
+ result = tee('abc', n)
+ self.assertEqual(type(result), tuple)
+ self.assertEqual(len(result), n)
+ self.assertEqual([list(x) for x in result], [list('abc')]*n)
+
+
+ # Tests not applicable to the tee() recipe
+ if False:
+ # tee pass-through to copyable iterator
+ a, b = tee('abc')
+ c, d = tee(a)
+ self.assertTrue(a is c)
+
+ # test tee_new
+ t1, t2 = tee('abc')
+ tnew = type(t1)
+ self.assertRaises(TypeError, tnew)
+ self.assertRaises(TypeError, tnew, 10)
+ t3 = tnew(t1)
+ self.assertTrue(list(t1) == list(t2) == list(t3) == list('abc'))
+
+ # test that tee objects are weak referencable
+ a, b = tee(range(10))
+ p = weakref.proxy(a)
+ self.assertEqual(getattr(p, '__class__'), type(b))
+ del a
+ gc.collect() # For PyPy or other GCs.
+ self.assertRaises(ReferenceError, getattr, p, '__class__')
+
+ ans = list('abc')
+ long_ans = list(range(10000))
+
+ # Tests not applicable to the tee() recipe
+ if False:
+ # check copy
+ a, b = tee('abc')
+ self.assertEqual(list(copy.copy(a)), ans)
+ self.assertEqual(list(copy.copy(b)), ans)
+ a, b = tee(list(range(10000)))
+ self.assertEqual(list(copy.copy(a)), long_ans)
+ self.assertEqual(list(copy.copy(b)), long_ans)
+
+ # check partially consumed copy
+ a, b = tee('abc')
+ take(2, a)
+ take(1, b)
+ self.assertEqual(list(copy.copy(a)), ans[2:])
+ self.assertEqual(list(copy.copy(b)), ans[1:])
+ self.assertEqual(list(a), ans[2:])
+ self.assertEqual(list(b), ans[1:])
+ a, b = tee(range(10000))
+ take(100, a)
+ take(60, b)
+ self.assertEqual(list(copy.copy(a)), long_ans[100:])
+ self.assertEqual(list(copy.copy(b)), long_ans[60:])
+ self.assertEqual(list(a), long_ans[100:])
+ self.assertEqual(list(b), long_ans[60:])
+
+ # Issue 13454: Crash when deleting backward iterator from tee()
+ forward, backward = tee(repeat(None, 2000)) # 20000000
+ try:
+ any(forward) # exhaust the iterator
+ del backward
+ except:
+ del forward, backward
+ raise
+
+
class TestGC(unittest.TestCase):
def makecycle(self, iterator, container):
projects / thirdparty / Python / cpython.git / commitdiff
