python类import_class()的实例源码

def get_config_hash(file_dir, resource_mapping, exts=['conf']):
    res = {}
    if not os.path.isdir(file_dir):
        logger.debug(
            "Directory {} not found. Returning emty dict".format(file_dir))
        return {}

    conf_files = [conf for conf in os.listdir(file_dir)
                  if conf.split('.')[-1] in exts]

    for conf_file in conf_files:
        if conf_file in resource_mapping.keys():
            drv = resource_mapping[conf_file].get(
                'driver',
                'fuel_external_git.drivers.openstack_config.OpenStackConfig'
            )
            drv_class = importutils.import_class(drv)
            config = drv_class(
                os.path.join(file_dir, conf_file),
                resource_mapping[conf_file]['resource']
            )
            deep_merge(res, config.to_config_dict())
    return res

def __init__(self, host, binary, topic, manager, report_interval=None,
                 periodic_interval=None, periodic_fuzzy_delay=None,
                 service_name=None, *args, **kwargs):
        super(Service, self).__init__()
        if not rpc.initialized():
            rpc.init(CONF)
        self.host = host
        self.binary = binary
        self.topic = topic
        self.manager_class_name = manager
        manager_class = importutils.import_class(self.manager_class_name)
        self.manager = manager_class(host=self.host,
                                     service_name=service_name,
                                     *args, **kwargs)
        self.report_interval = report_interval
        self.periodic_interval = periodic_interval
        self.periodic_fuzzy_delay = periodic_fuzzy_delay
        self.saved_args, self.saved_kwargs = args, kwargs
        self.timers = []

def _get_manager(self):
        """Initialize a Manager object appropriate for this service.

        Use the service name to look up a Manager subclass from the
        configuration and initialize an instance. If no class name
        is configured, just return None.

        :returns: a Manager instance, or None.

        """
        fl = '%s_manager' % self.name
        if fl not in CONF:
            return None

        manager_class_name = CONF.get(fl, None)
        if not manager_class_name:
            return None

        manager_class = importutils.import_class(manager_class_name)
        return manager_class()

def get_class(api_name, version, version_map):
        """Returns the client class for the requested API version

        :param api_name: the name of the API, e.g. 'compute', 'image', etc
        :param version: the requested API version
        :param version_map: a dict of client classes keyed by version
        :rtype: a client class for the requested API version
        """
        try:
            client_path = version_map[str(version)]
        except (KeyError, ValueError):
            msg = _("Invalid %(api_name)s client version '%(version)s'. "
                    "Must be one of: %(version_map)s") % {
                        'api_name': api_name,
                        'version': version,
                        'version_map': ', '.join(version_map.keys())}
            raise exceptions.UnsupportedVersion(msg)

        return importutils.import_class(client_path)

def get_matching_classes(self, loadable_class_names):
        """Get loadable classes from a list of names.

        Each name can be a full module path or the full path to a
        method that returns classes to use.  The latter behavior
        is useful to specify a method that returns a list of
        classes to use in a default case.
        """

        classes = []
        for cls_name in loadable_class_names:
            obj = importutils.import_class(cls_name)
            if self._is_correct_class(obj):
                classes.append(obj)
            elif inspect.isfunction(obj):
                # Get list of classes from a function
                for cls in obj():
                    classes.append(cls)
            else:
                error_str = 'Not a class of the correct type'
                raise exception.ClassNotFound(class_name=cls_name,
                                              exception=error_str)
        return classes

def get_client_class(api_name, version, version_map):
    """Returns the client class for the requested API version

    :param api_name: the name of the API, e.g. 'compute', 'image', etc
    :param version: the requested API version
    :param version_map: a dict of client classes keyed by version
    :rtype: a client class for the requested API version
    """
    try:
        client_path = version_map[str(version)]
    except (KeyError, ValueError):
        sorted_versions = sorted(version_map.keys(),
                                 key=lambda s: list(map(int, s.split('.'))))
        msg = _(
            "Invalid %(api_name)s client version '%(version)s'. "
            "must be one of: %(version_map)s"
        )
        raise exceptions.UnsupportedVersion(msg % {
            'api_name': api_name,
            'version': version,
            'version_map': ', '.join(sorted_versions),
        })

    return importutils.import_class(client_path)

def get_class(api_name, version, version_map):
        """Returns the client class for the requested API version

        :param api_name: the name of the API, e.g. 'compute', 'image', etc
        :param version: the requested API version
        :param version_map: a dict of client classes keyed by version
        :rtype: a client class for the requested API version
        """
        try:
            client_path = version_map[str(version)]
        except (KeyError, ValueError):
            msg = _("Invalid %(api_name)s client version '%(version)s'. "
                    "Must be one of: %(version_map)s") % {
                        'api_name': api_name,
                        'version': version,
                        'version_map': ', '.join(version_map.keys())}
            raise exceptions.UnsupportedVersion(msg)

        return importutils.import_class(client_path)

def get_class(api_name, version, version_map):
        """Returns the client class for the requested API version

        :param api_name: the name of the API, e.g. 'compute', 'image', etc
        :param version: the requested API version
        :param version_map: a dict of client classes keyed by version
        :rtype: a client class for the requested API version
        """
        try:
            client_path = version_map[str(version)]
        except (KeyError, ValueError):
            msg = _("Invalid %(api_name)s client version '%(version)s'. "
                    "Must be one of: %(version_map)s") % {
                        'api_name': api_name,
                        'version': version,
                        'version_map': ', '.join(version_map.keys())}
            raise exceptions.UnsupportedVersion(msg)

        return importutils.import_class(client_path)

def get_class(api_name, version, version_map):
        """Returns the client class for the requested API version

        :param api_name: the name of the API, e.g. 'compute', 'image', etc
        :param version: the requested API version
        :param version_map: a dict of client classes keyed by version
        :rtype: a client class for the requested API version
        """
        try:
            client_path = version_map[str(version)]
        except (KeyError, ValueError):
            msg = _("Invalid %(api_name)s client version '%(version)s'. "
                    "Must be one of: %(version_map)s") % {
                        'api_name': api_name,
                        'version': version,
                        'version_map': ', '.join(version_map.keys())}
            raise exceptions.UnsupportedVersion(msg)

        return importutils.import_class(client_path)

def get_class(api_name, version, version_map):
        """Returns the client class for the requested API version

        :param api_name: the name of the API, e.g. 'compute', 'image', etc
        :param version: the requested API version
        :param version_map: a dict of client classes keyed by version
        :rtype: a client class for the requested API version
        """
        try:
            client_path = version_map[str(version)]
        except (KeyError, ValueError):
            msg = _("Invalid %(api_name)s client version '%(version)s'. "
                    "Must be one of: %(version_map)s") % {
                        'api_name': api_name,
                        'version': version,
                        'version_map': ', '.join(version_map.keys())}
            raise exceptions.UnsupportedVersion(msg)

        return importutils.import_class(client_path)

def get_client_class(api_name, version, version_map):
    """Returns the client class for the requested API version.

    :param api_name: the name of the API, e.g. 'compute', 'image', etc
    :param version: the requested API version
    :param version_map: a dict of client classes keyed by version
    :rtype: a client class for the requested API version
    """
    try:
        client_path = version_map[str(version)]
    except (KeyError, ValueError):
        msg = _("Invalid %(api_name)s client version '%(version)s'. must be "
                "one of: %(map_keys)s")
        msg = msg % {'api_name': api_name, 'version': version,
                     'map_keys': ', '.join(version_map.keys())}
        raise exceptions.UnsupportedVersion(msg)

    return importutils.import_class(client_path)

def get_class(api_name, version, version_map):
        """Returns the client class for the requested API version

        :param api_name: the name of the API, e.g. 'compute', 'image', etc
        :param version: the requested API version
        :param version_map: a dict of client classes keyed by version
        :rtype: a client class for the requested API version
        """
        try:
            client_path = version_map[str(version)]
        except (KeyError, ValueError):
            msg = _("Invalid %(api_name)s client version '%(version)s'. "
                    "Must be one of: %(version_map)s") % {
                        'api_name': api_name,
                        'version': version,
                        'version_map': ', '.join(version_map.keys())}
            raise exceptions.UnsupportedVersion(msg)

        return importutils.import_class(client_path)

def __init__(self, host, binary, topic, manager,
                 periodic_enable=None, periodic_fuzzy_delay=None,
                 periodic_interval_max=None):
        super(Service, self).__init__()

        if not rpc.initialized():
            rpc.init(CONF)

        self.host = host
        self.binary = binary
        self.topic = topic
        self.manager_class_name = manager
        manager_class = importutils.import_class(self.manager_class_name)
        self.rpcserver = None
        self.manager = manager_class(host=self.host)
        self.periodic_enable = periodic_enable
        self.periodic_fuzzy_delay = periodic_fuzzy_delay
        self.periodic_interval_max = periodic_interval_max

def load_extension(self, ext_factory):
        """Execute an extension factory.

        Loads an extension.  The 'ext_factory' is the name of a
        callable that will be imported and called with one
        argument--the extension manager.  The factory callable is
        expected to call the register() method at least once.
        """

        LOG.debug("Loading extension %s", ext_factory)

        if isinstance(ext_factory, six.string_types):
            # Load the factory
            factory = importutils.import_class(ext_factory)
        else:
            factory = ext_factory

        # Call it
        LOG.debug("Calling extension factory %s", ext_factory)
        factory(self)

def get_matching_classes(self, loadable_class_names):
        """Get loadable classes from a list of names.  Each name can be
        a full module path or the full path to a method that returns
        classes to use.  The latter behavior is useful to specify a method
        that returns a list of classes to use in a default case.
        """
        classes = []
        for cls_name in loadable_class_names:
            obj = importutils.import_class(cls_name)
            if self._is_correct_class(obj):
                classes.append(obj)
            elif inspect.isfunction(obj):
                # Get list of classes from a function
                for cls in obj():
                    classes.append(cls)
            else:
                error_str = 'Not a class of the correct type'
                raise exception.ClassNotFound(class_name=cls_name,
                                              exception=error_str)
        return classes

def __init__(self, session, virtapi):
        self.compute_api = compute.API()
        self._session = session
        self._virtapi = virtapi
        self._volumeops = volumeops.VolumeOps(self._session)
        self.firewall_driver = firewall.load_driver(
            DEFAULT_FIREWALL_DRIVER,
            xenapi_session=self._session)
        vif_impl = importutils.import_class(CONF.xenserver.vif_driver)
        self.vif_driver = vif_impl(xenapi_session=self._session)
        self.default_root_dev = '/dev/sda'

        LOG.debug("Importing image upload handler: %s",
                  CONF.xenserver.image_upload_handler)
        self.image_upload_handler = importutils.import_object(
                                CONF.xenserver.image_upload_handler)

def __init__(self, host, binary, topic, manager, report_interval=None,
                 periodic_enable=None, periodic_fuzzy_delay=None,
                 periodic_interval_max=None, db_allowed=True,
                 *args, **kwargs):
        super(Service, self).__init__()
        self.host = host
        self.binary = binary
        self.topic = topic
        self.manager_class_name = manager
        self.servicegroup_api = servicegroup.API()
        manager_class = importutils.import_class(self.manager_class_name)
        self.manager = manager_class(host=self.host, *args, **kwargs)
        self.rpcserver = None
        self.report_interval = report_interval
        self.periodic_enable = periodic_enable
        self.periodic_fuzzy_delay = periodic_fuzzy_delay
        self.periodic_interval_max = periodic_interval_max
        self.saved_args, self.saved_kwargs = args, kwargs
        self.backdoor_port = None
        self.conductor_api = conductor.API(use_local=db_allowed)
        self.conductor_api.wait_until_ready(context.get_admin_context())

def _get_manager(self):
        """Initialize a Manager object appropriate for this service.

        Use the service name to look up a Manager subclass from the
        configuration and initialize an instance. If no class name
        is configured, just return None.

        :returns: a Manager instance, or None.

        """
        fl = '%s_manager' % self.name
        if fl not in CONF:
            return None

        manager_class_name = CONF.get(fl, None)
        if not manager_class_name:
            return None

        manager_class = importutils.import_class(manager_class_name)
        return manager_class()

def __init__(self, application, limits=None, limiter=None, **kwargs):
        """Initialize new `RateLimitingMiddleware`.

        It wraps the given WSGI application and sets up the given limits.

        @param application: WSGI application to wrap
        @param limits: String describing limits
        @param limiter: String identifying class for representing limits

        Other parameters are passed to the constructor for the limiter.
        """
        base_wsgi.Middleware.__init__(self, application)

        # Select the limiter class
        if limiter is None:
            limiter = Limiter
        else:
            limiter = importutils.import_class(limiter)

        # Parse the limits, if any are provided
        if limits is not None:
            limits = limiter.parse_limits(limits)

        self._limiter = limiter(limits or DEFAULT_LIMITS, **kwargs)

def __init__(self, *args, **kwargs):
        LOG.warning(_LW('The cells feature of Nova is considered experimental '
                        'by the OpenStack project because it receives much '
                        'less testing than the rest of Nova. This may change '
                        'in the future, but current deployers should be aware '
                        'that the use of it in production right now may be '
                        'risky. Also note that cells does not currently '
                        'support rolling upgrades, it is assumed that cells '
                        'deployments are upgraded lockstep so n-1 cells '
                        'compatibility does not work.'))
        # Mostly for tests.
        cell_state_manager = kwargs.pop('cell_state_manager', None)
        super(CellsManager, self).__init__(service_name='cells',
                                           *args, **kwargs)
        if cell_state_manager is None:
            cell_state_manager = cells_state.CellStateManager
        self.state_manager = cell_state_manager()
        self.msg_runner = messaging.MessageRunner(self.state_manager)
        cells_driver_cls = importutils.import_class(
                CONF.cells.driver)
        self.driver = cells_driver_cls()
        self.instances_to_heal = iter([])

def _parse_class_args(self):
        """Parse the contrailplugin.ini file.

        Opencontrail supports extension such as ipam, policy, these extensions
        can be configured in the plugin configuration file as shown below.
        Plugin then loads the specified extensions.
        contrail_extensions=ipam:<classpath>,policy:<classpath>
        """

        contrail_extensions = cfg.CONF.APISERVER.contrail_extensions
        # If multiple class specified for same extension, last one will win
        # according to DictOpt behavior
        for ext_name, ext_class in contrail_extensions.items():
            try:
                if not ext_class or ext_class == 'None':
                    self.supported_extension_aliases.append(ext_name)
                    continue
                ext_class = importutils.import_class(ext_class)
                ext_instance = ext_class()
                ext_instance.set_core(self)
                for method in dir(ext_instance):
                    for prefix in ['get', 'update', 'delete', 'create']:
                        if method.startswith('%s_' % prefix):
                            setattr(self, method,
                                    ext_instance.__getattribute__(method))
                self.supported_extension_aliases.append(ext_name)
            except Exception:
                LOG.exception("Contrail Backend Error")
                # Converting contrail backend error to Neutron Exception
                raise exceptions.InvalidContrailExtensionError(
                    ext_name=ext_name, ext_class=ext_class)
        self._build_auth_details()

def API():
    importutils = oslo_utils.importutils
    cluster_api_class = oslo_config.cfg.CONF.cluster_api_class
    cls = importutils.import_class(cluster_api_class)
    return cls()

def __init__(self, host, binary, manager):
        super(Service, self).__init__()
        self.host = host
        self.binary = binary
        self.manager_class_name = manager
        manager_class = importutils.import_class(self.manager_class_name)
        self.manager = manager_class(host=self.host)

def __init__(self, virtapi):
        super(DockerDriver, self).__init__(virtapi)
        self._docker = None
        vif_class = importutils.import_class(CONF.docker.vif_driver)
        self.vif_driver = vif_class()
        self.firewall_driver = firewall.load_driver(
            default='nova.virt.firewall.NoopFirewallDriver')
        # NOTE(zhangguoqing): For passing the nova unit tests
        self.active_migrations = {}

def test_all_public_methods_are_traced(self):
        profiler_opts.set_defaults(conf.CONF)
        self.config(enabled=True,
                    group='profiler')

        classes = [
            'zun.compute.api.API',
            'zun.compute.rpcapi.API',
        ]
        for clsname in classes:
            # give the metaclass and trace_cls() decorator a chance to patch
            # methods of the classes above
            six.reload_module(
                importutils.import_module(clsname.rsplit('.', 1)[0]))
            cls = importutils.import_class(clsname)

            for attr, obj in cls.__dict__.items():
                # only public methods are traced
                if attr.startswith('_'):
                    continue
                # only checks callables
                if not (inspect.ismethod(obj) or inspect.isfunction(obj)):
                    continue
                # osprofiler skips static methods
                if isinstance(obj, staticmethod):
                    continue

                self.assertTrue(getattr(obj, '__traced__', False), obj)

def setUp(self):
        super(TestShell, self).setUp()
        self.shell_class = importutils.import_class(self.shell_class_name)
        self.cmd_patch = mock.patch(self.shell_class_name + ".run_subcommand")
        self.cmd_save = self.cmd_patch.start()
        self.addCleanup(self.cmd_patch.stop)
        self.app = mock.Mock("Test Shell")

def test_import_class(self):
        dt = importutils.import_class('datetime.datetime')
        self.assertEqual(sys.modules['datetime'].datetime, dt)

def test_import_bad_class(self):
        self.assertRaises(ImportError, importutils.import_class,
                          'lol.u_mad.brah')

def _get_client_class_and_version(version):
    if not isinstance(version, api_versions.APIVersion):
        version = api_versions.get_api_version(version)
    else:
        api_versions.check_major_version(version)
    if version.is_latest():
        raise exceptions.UnsupportedVersion(("The version should be explicit, "
                                             "not latest."))
    return version, importutils.import_class(
        "harborclient.v%s.client.Client" % version.ver_major)

def _get_connector(self):
        connector = cinder_conf.volume_connector
        if not connector or connector not in volume_connector_conf:
            msg = _("Must provide an valid volume connector")
            LOG.error(msg)
            raise exceptions.FuxiException(msg)
        return importutils.import_class(volume_connector_conf[connector])()