Python collections.Iterator() Examples

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_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 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 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 _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 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 _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 _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 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_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_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 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 cons(head, tail):
    if isinstance(tail, Iterator):
        return chain((head,), tail)
    if isinstance(tail, cell):
        return cell(head, tail)
    if tail is None:
        return cell(head, None)
    return (head,) + tail 

def test_map(resources):
    with MesosPoolExecutor(name='futures-pool') as executor:
        it = executor.map(operator.add, range(10), range(10),
                          resources=resources)
        assert isinstance(it, Iterator)
        for i, v in enumerate(it):
            assert i + i == v 

def _clean_feature_columns(feature_columns):
  """Verifies and normalizes `feature_columns` input."""
  if isinstance(feature_columns, _FeatureColumn):
    feature_columns = [feature_columns]

  if isinstance(feature_columns, collections.Iterator):
    feature_columns = list(feature_columns)

  if isinstance(feature_columns, dict):
    raise ValueError('Expected feature_columns to be iterable, found dict.')

  for column in feature_columns:
    if not isinstance(column, _FeatureColumn):
      raise ValueError('Items of feature_columns must be a _FeatureColumn. '
                       'Given (type {}): {}.'.format(type(column), column))
  if not feature_columns:
    raise ValueError('feature_columns must not be empty.')
  name_to_column = dict()
  for column in feature_columns:
    if column.name in name_to_column:
      raise ValueError('Duplicate feature column name found for columns: {} '
                       'and {}. This usually means that these columns refer to '
                       'same base feature. Either one must be discarded or a '
                       'duplicated but renamed item must be inserted in '
                       'features dict.'.format(column,
                                               name_to_column[column.name]))
    name_to_column[column.name] = column

  return feature_columns 

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.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 is_iterator(x):
    """An implementation independent way of checking for iterators

    Python 2.6 has a different implementation of collections.Iterator which
    accepts anything with a `next` method. 2.7+ requires and `__iter__` method
    as well.
    """
    if sys.version_info >= (2, 7):
        return isinstance(x, collections.Iterator)
    return isinstance(x, collections.Iterator) and hasattr(x, '__iter__') 

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 _item_to_table(iterator, resource):
    """Convert a JSON table to the native object.

    Args:
        iterator (google.api_core.page_iterator.Iterator): The iterator that is currently in use.

        resource (Dict): An item to be converted to a table.

    Returns:
        google.cloud.bigquery.table.Table: The next table in the page.
    """
    return TableListItem(resource) 

def _item_to_routine(iterator, resource):
    """Convert a JSON model to the native object.

    Args:
        iterator (google.api_core.page_iterator.Iterator):
            The iterator that is currently in use.
        resource (Dict): An item to be converted to a routine.

    Returns:
        google.cloud.bigquery.routine.Routine: The next routine in the page.
    """
    return Routine.from_api_repr(resource) 

def _item_to_job(iterator, resource):
    """Convert a JSON job to the native object.

    Args:
        iterator (google.api_core.page_iterator.Iterator): The iterator that is currently in use.

        resource (Dict): An item to be converted to a job.

    Returns:
        job instance: The next job in the page.
    """
    return iterator.client.job_from_resource(resource) 

def _item_to_dataset(iterator, resource):
    """Convert a JSON dataset to the native object.

    Args:
        iterator (google.api_core.page_iterator.Iterator): The iterator that is currently in use.

        resource (Dict): An item to be converted to a dataset.

    Returns:
        google.cloud.bigquery.dataset.DatasetListItem: The next dataset in the page.
    """
    return DatasetListItem(resource) 

def _item_to_project(iterator, resource):
    """Convert a JSON project to the native object.

    Args:
        iterator (google.api_core.page_iterator.Iterator): The iterator that is currently in use.

        resource (Dict): An item to be converted to a project.

    Returns:
        google.cloud.bigquery.client.Project: The next project in the page.
    """
    return Project.from_api_repr(resource)


# pylint: enable=unused-argument 

def list_projects(
        self, max_results=None, page_token=None, retry=DEFAULT_RETRY, timeout=None
    ):
        """List projects for the project associated with this client.

        See
        https://cloud.google.com/bigquery/docs/reference/rest/v2/projects/list

        Args:
            max_results (Optional[int]):
                Maximum number of projects to return, If not passed,
                defaults to a value set by the API.

            page_token (Optional[str]):
                Token representing a cursor into the projects. If not passed,
                the API will return the first page of projects. The token marks
                the beginning of the iterator to be returned and the value of
                the ``page_token`` can be accessed at ``next_page_token`` of the
                :class:`~google.api_core.page_iterator.HTTPIterator`.

            retry (Optional[google.api_core.retry.Retry]): How to retry the RPC.

            timeout (Optional[float]):
                The number of seconds to wait for the underlying HTTP transport
                before using ``retry``.

        Returns:
            google.api_core.page_iterator.Iterator:
                Iterator of :class:`~google.cloud.bigquery.client.Project`
                accessible to the current client.
        """
        return page_iterator.HTTPIterator(
            client=self,
            api_request=functools.partial(self._call_api, retry, timeout=timeout),
            path="/projects",
            item_to_value=_item_to_project,
            items_key="projects",
            page_token=page_token,
            max_results=max_results,
        ) 

def wait_instances_running(ec2, instances):
    """
    Wait until no instance in the given iterable is 'pending'. Yield every instance that
    entered the running state as soon as it does.

    :param boto.ec2.connection.EC2Connection ec2: the EC2 connection to use for making requests
    :param Iterator[Instance] instances: the instances to wait on
    :rtype: Iterator[Instance]
    """
    running_ids = set()
    other_ids = set()
    while True:
        pending_ids = set()
        for i in instances:
            if i.state == 'pending':
                pending_ids.add(i.id)
            elif i.state == 'running':
                assert i.id not in running_ids
                running_ids.add(i.id)
                yield i
            else:
                assert i.id not in other_ids
                other_ids.add(i.id)
                yield i
        log.info('%i instance(s) pending, %i running, %i other.',
                 *map(len, (pending_ids, running_ids, other_ids)))
        if not pending_ids:
            break
        seconds = max(a_short_time, min(len(pending_ids), 10 * a_short_time))
        log.info('Sleeping for %is', seconds)
        time.sleep(seconds)
        for attempt in retry_ec2():
            with attempt:
                instances = ec2.get_only_instances(list(pending_ids)) 

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