Python collections.Iterator() Examples

def _standardize_value(self, value):
        reader, fsize, fname = (value + [None, None])[:3]

        if isinstance(reader, file):
            reader = self._make_file_reader(reader)

        elif isinstance(reader, str):
            reader = self._make_str_reader(reader)
            fsize = len(value[0])

        elif isinstance(reader, Iterator):
            pass

        else:
            raise InvalidArgumentTypeError('type of value[0] {x}'
                'is invalid'.format(x=type(value[0])))

        return reader, fsize, fname 

def axis_iter(self, axes=0):
        """Returns an iterator yielding Sub-MPArrays of ``self`` by iterating
        over the specified physical axes.

        **Example:** If ``self`` represents a bipartite (i.e. length 2)
        array with 2 physical dimensions on each site ``A[(k,l), (m,n)]``,
        ``self.axis_iter(0)`` is equivalent to::

            (A[(k, :), (m, :)] for m in range(...) for k in range(...))

        :param axes: Iterable or int specifiying the physical axes to iterate
            over (default 0 for each site)
        :returns: Iterator over :class:`.MPArray`

        """
        if not isinstance(axes, collections.Iterable):
            axes = it.repeat(axes, len(self))

        ltens_iter = it.product(*(iter(np.rollaxis(lten, i + 1))
                                  for i, lten in zip(axes, self.lt)))
        return (MPArray(ltens) for ltens in ltens_iter)

    ##########################
    #  Algebraic operations  #
    ########################## 

def _extract_factors(tens, ndims):
    """Extract iteratively the leftmost MPO tensor with given number of
    legs by a qr-decomposition

    :param np.ndarray tens: Full tensor to be factorized
    :param ndims: Number of physical legs per site or iterator over number of
        physical legs
    :returns: List of local tensors with given number of legs yielding a
        factorization of tens
    """
    current = next(ndims) if isinstance(ndims, collections.Iterator) else ndims
    if tens.ndim == current + 2:
        return [tens]
    elif tens.ndim < current + 2:
        raise AssertionError("Number of remaining legs insufficient.")
    else:
        unitary, rest = qr(tens.reshape((np.prod(tens.shape[:current + 1]), -1)))

        unitary = unitary.reshape(tens.shape[:current + 1] + rest.shape[:1])
        rest = rest.reshape(rest.shape[:1] + tens.shape[current + 1:])

        return [unitary] + _extract_factors(rest, ndims) 

def _ltens_to_array(ltens):
    """Computes the full array representation from an iterator yielding the
    local tensors. Note that it does not get rid of virtual legs.

    :param ltens: Iterator over local tensors
    :returns: numpy.ndarray representing the contracted MPA

    """
    ltens = ltens if isinstance(ltens, collections.Iterator) else iter(ltens)
    res = first = next(ltens)
    for tens in ltens:
        res = matdot(res, tens)
    if res is first:
        # Always return a writable array, even if len(ltens) == 1.
        res = res.copy()
    return res


################################################
#  Helper methods for variational compression  #
################################################ 

def test_glob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.glob("fileA")
        self.assertIsInstance(it, collections.Iterator)
        _check(it, ["fileA"])
        _check(p.glob("fileB"), [])
        _check(p.glob("dir*/file*"), ["dirB/fileB", "dirC/fileC"])
        if symlink_skip_reason:
            _check(p.glob("*A"), ['dirA', 'fileA'])
        else:
            _check(p.glob("*A"), ['dirA', 'fileA', 'linkA'])
        if symlink_skip_reason:
            _check(p.glob("*B/*"), ['dirB/fileB'])
        else:
            _check(p.glob("*B/*"), ['dirB/fileB', 'dirB/linkD',
                                    'linkB/fileB', 'linkB/linkD'])
        if symlink_skip_reason:
            _check(p.glob("*/fileB"), ['dirB/fileB'])
        else:
            _check(p.glob("*/fileB"), ['dirB/fileB', 'linkB/fileB']) 

def test_rglob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.rglob("fileA")
        self.assertIsInstance(it, collections.Iterator)
        # XXX cannot test because of symlink loops in the test setup
        #_check(it, ["fileA"])
        #_check(p.rglob("fileB"), ["dirB/fileB"])
        #_check(p.rglob("*/fileA"), [""])
        #_check(p.rglob("*/fileB"), ["dirB/fileB"])
        #_check(p.rglob("file*"), ["fileA", "dirB/fileB"])
        # No symlink loops here
        p = P(BASE, "dirC")
        _check(p.rglob("file*"), ["dirC/fileC", "dirC/dirD/fileD"])
        _check(p.rglob("*/*"), ["dirC/dirD/fileD"]) 

def test_glob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.glob("fileA")
        self.assertIsInstance(it, collections.Iterator)
        _check(it, ["fileA"])
        _check(p.glob("fileB"), [])
        _check(p.glob("dir*/file*"), ["dirB/fileB", "dirC/fileC"])
        if symlink_skip_reason:
            _check(p.glob("*A"), ['dirA', 'fileA'])
        else:
            _check(p.glob("*A"), ['dirA', 'fileA', 'linkA'])
        if symlink_skip_reason:
            _check(p.glob("*B/*"), ['dirB/fileB'])
        else:
            _check(p.glob("*B/*"), ['dirB/fileB', 'dirB/linkD',
                                    'linkB/fileB', 'linkB/linkD'])
        if symlink_skip_reason:
            _check(p.glob("*/fileB"), ['dirB/fileB'])
        else:
            _check(p.glob("*/fileB"), ['dirB/fileB', 'linkB/fileB']) 

def test_rglob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.rglob("fileA")
        self.assertIsInstance(it, collections.Iterator)
        _check(it, ["fileA"])
        _check(p.rglob("fileB"), ["dirB/fileB"])
        _check(p.rglob("*/fileA"), [])
        if symlink_skip_reason:
            _check(p.rglob("*/fileB"), ["dirB/fileB"])
        else:
            _check(p.rglob("*/fileB"), ["dirB/fileB", "dirB/linkD/fileB",
                                        "linkB/fileB", "dirA/linkC/fileB"])
        _check(p.rglob("file*"), ["fileA", "dirB/fileB",
                                  "dirC/fileC", "dirC/dirD/fileD"])
        p = P(BASE, "dirC")
        _check(p.rglob("file*"), ["dirC/fileC", "dirC/dirD/fileD"])
        _check(p.rglob("*/*"), ["dirC/dirD/fileD"]) 

def test_glob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.glob("fileA")
        self.assertIsInstance(it, collections.Iterator)
        _check(it, ["fileA"])
        _check(p.glob("fileB"), [])
        _check(p.glob("dir*/file*"), ["dirB/fileB", "dirC/fileC"])
        if symlink_skip_reason:
            _check(p.glob("*A"), ['dirA', 'fileA'])
        else:
            _check(p.glob("*A"), ['dirA', 'fileA', 'linkA'])
        if symlink_skip_reason:
            _check(p.glob("*B/*"), ['dirB/fileB'])
        else:
            _check(p.glob("*B/*"), ['dirB/fileB', 'dirB/linkD',
                                    'linkB/fileB', 'linkB/linkD'])
        if symlink_skip_reason:
            _check(p.glob("*/fileB"), ['dirB/fileB'])
        else:
            _check(p.glob("*/fileB"), ['dirB/fileB', 'linkB/fileB']) 

def test_rglob_common(self):
        def _check(glob, expected):
            self.assertEqual(set(glob), { P(BASE, q) for q in expected })
        P = self.cls
        p = P(BASE)
        it = p.rglob("fileA")
        self.assertIsInstance(it, collections.Iterator)
        _check(it, ["fileA"])
        _check(p.rglob("fileB"), ["dirB/fileB"])
        _check(p.rglob("*/fileA"), [])
        if symlink_skip_reason:
            _check(p.rglob("*/fileB"), ["dirB/fileB"])
        else:
            _check(p.rglob("*/fileB"), ["dirB/fileB", "dirB/linkD/fileB",
                                        "linkB/fileB", "dirA/linkC/fileB"])
        _check(p.rglob("file*"), ["fileA", "dirB/fileB",
                                  "dirC/fileC", "dirC/dirD/fileD"])
        p = P(BASE, "dirC")
        _check(p.rglob("file*"), ["dirC/fileC", "dirC/dirD/fileD"])
        _check(p.rglob("*/*"), ["dirC/dirD/fileD"]) 

def testIsIterator():
    print("是否为Iterable对象：")
    print(isinstance([], Iterable))
    print(isinstance({}, Iterable))
    print(isinstance((1, 2, 3), Iterable))
    print(isinstance(set([1, 2, 3]), Iterable))
    print(isinstance("string", Iterable))
    print(isinstance(gen, Iterable))
    print(isinstance(fibonacci(10), Iterable))
    print("是否为Iterator对象：")
    print(isinstance([], Iterator))
    print(isinstance({}, Iterator))
    print(isinstance((1, 2, 3), Iterator))
    print(isinstance(set([1, 2, 3]), Iterator))
    print(isinstance("string", Iterator))
    print(isinstance(gen, Iterator))
    print(isinstance(fibonacci(10), Iterator)) 

def _prepare_data(self, data):
        """
        Prepare data for addition to the tree. If the data is a list or tuple,
        it is expected to be of the form (obj, lookup_type, value), where obj
        is a Constraint object, and is then slightly munged before being
        stored (to avoid storing any reference to field objects). Otherwise,
        the 'data' is stored unchanged and can be any class with an 'as_sql()'
        method.
        """
        if not isinstance(data, (list, tuple)):
            return data
        obj, lookup_type, value = data
        if isinstance(value, collections.Iterator):
            # Consume any generators immediately, so that we can determine
            # emptiness and transform any non-empty values correctly.
            value = list(value)

        # The "value_annotation" parameter is used to pass auxiliary information
        # about the value(s) to the query construction. Specifically, datetime
        # and empty values need special handling. Other types could be used
        # here in the future (using Python types is suggested for consistency).
        if (isinstance(value, datetime.datetime)
                or (isinstance(obj.field, DateTimeField) and lookup_type != 'isnull')):
            value_annotation = datetime.datetime
        elif hasattr(value, 'value_annotation'):
            value_annotation = value.value_annotation
        else:
            value_annotation = bool(value)

        if hasattr(obj, 'prepare'):
            value = obj.prepare(lookup_type, value)
        return (obj, lookup_type, value_annotation, value) 

def _get_choices(self):
        if isinstance(self._choices, collections.Iterator):
            choices, self._choices = tee(self._choices)
            return choices
        else:
            return self._choices 

def test_Iterator(self):
        non_samples = [None, 42, 3.14, 1j, "".encode('ascii'), "", (), [],
            {}, set()]
        for x in non_samples:
            self.assertNotIsInstance(x, Iterator)
            self.assertFalse(issubclass(type(x), Iterator), repr(type(x)))
        samples = [iter(str()),
                   iter(tuple()), iter(list()), iter(dict()),
                   iter(set()), iter(frozenset()),
                   iter(dict().keys()), iter(dict().items()),
                   iter(dict().values()),
                   (lambda: (yield))(),
                   (x for x in []),
                   ]
        for x in samples:
            self.assertIsInstance(x, Iterator)
            self.assertTrue(issubclass(type(x), Iterator), repr(type(x)))
        self.validate_abstract_methods(Iterator, 'next', '__iter__')

        # Issue 10565
        class NextOnly:
            def __next__(self):
                yield 1
                raise StopIteration
        self.assertNotIsInstance(NextOnly(), Iterator)
        class NextOnlyNew(object):
            def __next__(self):
                yield 1
                raise StopIteration
        self.assertNotIsInstance(NextOnlyNew(), Iterator) 

def test_direct_subclassing(self):
        for B in Hashable, Iterable, Iterator, Sized, Container, Callable:
            class C(B):
                pass
            self.assertTrue(issubclass(C, B))
            self.assertFalse(issubclass(int, C)) 

def test_registration(self):
        for B in Hashable, Iterable, Iterator, Sized, Container, Callable:
            class C:
                __metaclass__ = type
                __hash__ = None  # Make sure it isn't hashable by default
            self.assertFalse(issubclass(C, B), B.__name__)
            B.register(C)
            self.assertTrue(issubclass(C, B)) 

def test_iter(self):
        self.assertIsInstance(languages, collections.Iterable)
        self.assertIsInstance(iter(languages), collections.Iterator) 

def testMyIteratableObj():
    myList = MyList()
    print("iterator是迭代器：%s" % isinstance(iter(myList), Iterator))

    print("myList是可迭代的对象：%s" % isinstance(myList, Iterable))

    for temp in myList:
        print(temp) 

def process_all_samples(input_files_pattern: str)-> Iterator:
    all_files = glob.glob(input_files_pattern)
    with mp.Pool() as p:
        for processed_samples in p.imap_unordered(process_file, all_files, chunksize=1):
            yield from processed_samples 

def test_Iterator(self):
        non_samples = [None, 42, 3.14, 1j, "".encode('ascii'), "", (), [],
            {}, set()]
        for x in non_samples:
            self.assertNotIsInstance(x, Iterator)
            self.assertFalse(issubclass(type(x), Iterator), repr(type(x)))
        samples = [iter(str()),
                   iter(tuple()), iter(list()), iter(dict()),
                   iter(set()), iter(frozenset()),
                   iter(dict().keys()), iter(dict().items()),
                   iter(dict().values()),
                   (lambda: (yield))(),
                   (x for x in []),
                   ]
        for x in samples:
            self.assertIsInstance(x, Iterator)
            self.assertTrue(issubclass(type(x), Iterator), repr(type(x)))
        self.validate_abstract_methods(Iterator, 'next', '__iter__')

        # Issue 10565
        class NextOnly:
            def __next__(self):
                yield 1
                raise StopIteration
        self.assertNotIsInstance(NextOnly(), Iterator)
        class NextOnlyNew(object):
            def __next__(self):
                yield 1
                raise StopIteration
        self.assertNotIsInstance(NextOnlyNew(), Iterator) 

def test_direct_subclassing(self):
        for B in Hashable, Iterable, Iterator, Sized, Container, Callable:
            class C(B):
                pass
            self.assertTrue(issubclass(C, B))
            self.assertFalse(issubclass(int, C)) 

def test_registration(self):
        for B in Hashable, Iterable, Iterator, Sized, Container, Callable:
            class C:
                __metaclass__ = type
                __hash__ = None  # Make sure it isn't hashable by default
            self.assertFalse(issubclass(C, B), B.__name__)
            B.register(C)
            self.assertTrue(issubclass(C, B)) 

def test_iterator(self):
        # deprecated feature
        bqm = dimod.BinaryQuadraticModel.from_ising({}, {'ab': -1})
        sampleset = dimod.SampleSet.from_samples_bqm([{'a': -1, 'b': 1}, {'a': 1, 'b': 1}], bqm)
        self.assertIsInstance(sampleset.samples(), abc.Iterator)
        self.assertIsInstance(sampleset.samples(n=2), abc.Iterator)
        spl = next(sampleset.samples())
        self.assertEqual(spl, {'a': 1, 'b': 1}) 

def test_Iterator(self):
        non_samples = [None, 42, 3.14, 1j, "".encode('ascii'), "", (), [],
            {}, set()]
        for x in non_samples:
            self.assertNotIsInstance(x, Iterator)
            self.assertFalse(issubclass(type(x), Iterator), repr(type(x)))
        samples = [iter(str()),
                   iter(tuple()), iter(list()), iter(dict()),
                   iter(set()), iter(frozenset()),
                   iter(dict().keys()), iter(dict().items()),
                   iter(dict().values()),
                   (lambda: (yield))(),
                   (x for x in []),
                   ]
        for x in samples:
            self.assertIsInstance(x, Iterator)
            self.assertTrue(issubclass(type(x), Iterator), repr(type(x)))
        self.validate_abstract_methods(Iterator, 'next', '__iter__')

        # Issue 10565
        class NextOnly:
            def __next__(self):
                yield 1
                raise StopIteration
        self.assertNotIsInstance(NextOnly(), Iterator)
        class NextOnlyNew(object):
            def __next__(self):
                yield 1
                raise StopIteration
        self.assertNotIsInstance(NextOnlyNew(), Iterator) 

def test_direct_subclassing(self):
        for B in Hashable, Iterable, Iterator, Sized, Container, Callable:
            class C(B):
                pass
            self.assertTrue(issubclass(C, B))
            self.assertFalse(issubclass(int, C)) 

def test_registration(self):
        for B in Hashable, Iterable, Iterator, Sized, Container, Callable:
            class C:
                __metaclass__ = type
                __hash__ = None  # Make sure it isn't hashable by default
            self.assertFalse(issubclass(C, B), B.__name__)
            B.register(C)
            self.assertTrue(issubclass(C, B)) 

def safe_first_element(obj):
    if isinstance(obj, collections.abc.Iterator):
        # needed to accept `array.flat` as input.
        # np.flatiter reports as an instance of collections.Iterator
        # but can still be indexed via [].
        # This has the side effect of re-setting the iterator, but
        # that is acceptable.
        try:
            return obj[0]
        except TypeError:
            pass
        raise RuntimeError("matplotlib does not support generators "
                           "as input")
    return next(iter(obj)) 

def _test(self, input):
        result = iter_nonfalse_unique(input)
        self.assertIsInstance(result, Iterator)
        self.assertEqual(list(result), self.EXPECTED_SEQ) 

def test_range(self):
        self.assertTrue(isinstance(range(0), Sequence))
        self.assertTrue(isinstance(reversed(range(0)), Iterator)) 

def safe_first_element(obj):
    if isinstance(obj, collections.abc.Iterator):
        # needed to accept `array.flat` as input.
        # np.flatiter reports as an instance of collections.Iterator
        # but can still be indexed via [].
        # This has the side effect of re-setting the iterator, but
        # that is acceptable.
        try:
            return obj[0]
        except TypeError:
            pass
        raise RuntimeError("matplotlib does not support generators "
                           "as input")
    return next(iter(obj))