pybis.py

        criteria = {
            "criteria": sub_criteria,
            "@type": "as.dto.dataset.search.DataSetSearchCriteria",
            "operator": "AND"
        }

        fetchopts = {
            "containers": {"@type": "as.dto.dataset.fetchoptions.DataSetFetchOptions"},
            "type": {"@type": "as.dto.dataset.fetchoptions.DataSetTypeFetchOptions"}
        }

        for option in ['tags', 'properties', 'sample', 'experiment', 'physicalData']:
            fetchopts[option] = fetch_option[option]

        request = {
            "method": "searchDataSets",
            "params": [self.token,
                       criteria,
                       fetchopts,
                       ],
        }
        resp = self._post_request(self.as_v3, request)
        if len(resp['objects']) == 0:
            raise ValueError("no datasets found!")

        objects = resp['objects']
        parse_jackson(objects)

        datasets = DataFrame(objects)
        datasets['registrationDate'] = datasets['registrationDate'].map(format_timestamp)
        datasets['modificationDate'] = datasets['modificationDate'].map(format_timestamp)
        datasets['experiment'] = datasets['experiment'].map(extract_nested_identifier)
        datasets['sample'] = datasets['sample'].map(extract_nested_identifier)
        datasets['type'] = datasets['type'].map(extract_code)
        datasets['permId'] = datasets['code']
        datasets['location'] = datasets['physicalData'].map(lambda x: x.get('location') if x else '')

        attrs = ['permId', 'properties', 'type', 'experiment', 'sample', 'registrationDate', 'modificationDate',
                 'location']
        if props is not None:
            for prop in props:
                datasets[prop.upper()] = datasets['properties'].map(lambda x: x.get(prop.upper(), ''))
                attrs.append(prop.upper())

        return Things(self, 'dataset', datasets[attrs], 'permId')

    def get_experiment(self, expId, withAttachments=False):
        """ Returns an experiment object for a given identifier (expId).
        """

        fetchopts = {
            "@type": "as.dto.experiment.fetchoptions.ExperimentFetchOptions",
            "type": {
                "@type": "as.dto.experiment.fetchoptions.ExperimentTypeFetchOptions",
            },
        }

        search_request = search_request_for_identifier(expId, 'experiment')
        for option in ['tags', 'properties', 'attachments', 'project', 'samples']:
            fetchopts[option] = fetch_option[option]

        if withAttachments:
            fetchopts['attachments'] = fetch_option['attachmentsWithContent']

        request = {
            "method": "getExperiments",
            "params": [
                self.token,
                [search_request],
                fetchopts
            ],
        }
        resp = self._post_request(self.as_v3, request)
        if len(resp) == 0:
            raise ValueError("No such experiment: %s" % expId)
        return Experiment(self,
                          self.get_experiment_type(resp[expId]["type"]["code"]),
                          resp[expId]
                          )

    def new_experiment(self, type, props=None, **kwargs):
        """ Creates a new experiment of a given experiment type.
        """
        return Experiment(self, self.get_experiment_type(type), None, props, **kwargs)

    def update_experiment(self, experimentId, properties=None, tagIds=None, attachments=None):
        params = {
            "experimentId": {
                "permId": experimentId,
                "@type": "as.dto.experiment.id.ExperimentPermId"
            },
            "@type": "as.dto.experiment.update.ExperimentUpdate"
        }
        if properties is not None:
            params["properties"] = properties
        if tagIds is not None:
            params["tagIds"] = tagIds
        if attachments is not None:
            params["attachments"] = attachments

        request = {
            "method": "updateExperiments",
            "params": [
                self.token,
                [params]
            ]
        }
        self._post_request(self.as_v3, request)

    def create_sample(self, space_ident, code, type,
                      project_ident=None, experiment_ident=None, properties=None, attachments=None, tags=None):

        tagIds = _create_tagIds(tags)
        typeId = _create_typeId(type)
        projectId = _create_projectId(project_ident)
        experimentId = _create_experimentId(experiment_ident)

        if properties is None:
            properties = {}

        request = {
            "method": "createSamples",
            "params": [
                self.token,
                [
                    {
                        "properties": properties,
                        "code": code,
                        "typeId": typeId,
                        "projectId": projectId,
                        "experimentId": experimentId,
                        "tagIds": tagIds,
                        "attachments": attachments,
                        "@type": "as.dto.sample.create.SampleCreation",
                    }
                ]
            ],
        }
        resp = self._post_request(self.as_v3, request)
        return self.get_sample(resp[0]['permId'])

    def create_external_data_management_system(self, code, label, address, address_type='FILE_SYSTEM'):
        """Create an external DMS.
        :param code: An openBIS code for the external DMS.
        :param label: A human-readable label.
        :param address: The address for accessing the external DMS. E.g., a URL.
        :param address_type: One of OPENBIS, URL, or FILE_SYSTEM
        :return:
        """
        request = {
            "method": "createExternalDataManagementSystems",
            "params": [
                self.token,
                [
                    {
                        "code": code,
                        "label": label,
                        "addressType": address_type,
                        "address": address,
                        "@type": "as.dto.externaldms.create.ExternalDmsCreation",
                    }
                ]
            ],
        }
        resp = self._post_request(self.as_v3, request)
        return self.get_external_data_management_system(resp[0]['permId'])

    def update_sample(self, sampleId, space=None, project=None, experiment=None,
                      parents=None, children=None, components=None, properties=None, tagIds=None, attachments=None):
        params = {
            "sampleId": {
                "permId": sampleId,
                "@type": "as.dto.sample.id.SamplePermId"
            },
            "@type": "as.dto.sample.update.SampleUpdate"
        }
        if space is not None:
            params['spaceId'] = space
        if project is not None:
            params['projectId'] = project
        if properties is not None:
            params["properties"] = properties
        if tagIds is not None:
            params["tagIds"] = tagIds
        if attachments is not None:
            params["attachments"] = attachments

        request = {
            "method": "updateSamples",
            "params": [
                self.token,
                [params]
            ]
        }
        self._post_request(self.as_v3, request)

    def delete_entity(self, entity, permid, reason, capitalize=True):
        """Deletes Spaces, Projects, Experiments, Samples and DataSets
        """

        if capitalize:
            entity_capitalized = entity.capitalize()
        else:
            entity_capitalized = entity

        entity_type = "as.dto.{}.id.{}PermId".format(entity.lower(), entity_capitalized)
        request = {
            "method": "delete" + entity_capitalized + 's',
            "params": [
                self.token,
                [
                    {
                        "permId": permid,
                        "@type": entity_type
                    }
                ],
                {
                    "reason": reason,
                    "@type": "as.dto.{}.delete.{}DeletionOptions".format(entity.lower(), entity_capitalized)
                }
            ]
        }
        self._post_request(self.as_v3, request)

    def get_deletions(self):
        request = {
            "method": "searchDeletions",
            "params": [
                self.token,
                {},
                {
                    "deletedObjects": {
                        "@type": "as.dto.deletion.fetchoptions.DeletedObjectFetchOptions"
                    }
                }
            ]
        }
        resp = self._post_request(self.as_v3, request)
        objects = resp['objects']
        parse_jackson(objects)

        new_objs = []
        for value in objects:
            del_objs = extract_deletion(value)
            if len(del_objs) > 0:
                new_objs.append(*del_objs)

        return DataFrame(new_objs)

    def new_project(self, space, code, description=None, **kwargs):
        return Project(self, None, space=space, code=code, description=description, **kwargs)

    def _gen_fetchoptions(self, options):
        fo = {}
        for option in options:
            fo[option] = fetch_option[option]
        return fo

    def get_project(self, projectId):
        options = ['space', 'registrator', 'modifier', 'attachments']
        if is_identifier(projectId):
            request = self._create_get_request(
                'getProjects', 'project', projectId, options
            )
            resp = self._post_request(self.as_v3, request)
            return Project(self, resp[projectId])

        else:
            search_criteria = _gen_search_criteria({
                'project': 'Project',
                'operator': 'AND',
                'code': projectId
            })
            fo = self._gen_fetchoptions(options)
            request = {
                "method": "searchProjects",
                "params": [self.token, search_criteria, fo]
            }
            resp = self._post_request(self.as_v3, request)
            return Project(self, resp['objects'][0])

    def get_projects(self, space=None):
        """ Get a list of all available projects (DataFrame object).
        """

        sub_criteria = []
        if space:
            sub_criteria.append(_subcriteria_for_code(space, 'space'))

        criteria = {
            "criteria": sub_criteria,
            "@type": "as.dto.project.search.ProjectSearchCriteria",
            "operator": "AND"
        }

        fetchopts = {"@type": "as.dto.project.fetchoptions.ProjectFetchOptions"}
        for option in ['registrator', 'modifier', 'leader']:
            fetchopts[option] = fetch_option[option]

        request = {
            "method": "searchProjects",
            "params": [self.token,
                       criteria,
                       fetchopts,
                       ],
        }

        resp = self._post_request(self.as_v3, request)
        if resp is not None:
            objects = resp['objects']
            parse_jackson(objects)

            projects = DataFrame(objects)
            if len(projects) is 0:
                raise ValueError("No projects found!")

            projects['registrationDate'] = projects['registrationDate'].map(format_timestamp)
            projects['modificationDate'] = projects['modificationDate'].map(format_timestamp)
            projects['leader'] = projects['leader'].map(extract_person)
            projects['registrator'] = projects['registrator'].map(extract_person)
            projects['modifier'] = projects['modifier'].map(extract_person)
            projects['permId'] = projects['permId'].map(extract_permid)
            projects['identifier'] = projects['identifier'].map(extract_identifier)

            pros = projects[['identifier', 'permId', 'leader', 'registrator', 'registrationDate',
                             'modifier', 'modificationDate']]
            return Things(self, 'project', pros, 'identifier')
        else:
            raise ValueError("No projects found!")

    def _create_get_request(self, method_name, entity, permids, options):

        if not isinstance(permids, list):
            permids = [permids]

        type = "as.dto.{}.id.{}".format(entity.lower(), entity.capitalize())
        search_params = []
        for permid in permids:
            # decide if we got a permId or an identifier
            match = re.match('/', permid)
            if match:
                search_params.append(
                    {"identifier": permid, "@type": type + 'Identifier'}
                )
            else:
                search_params.append(
                    {"permId": permid, "@type": type + 'PermId'}
                )

        fo = {}
        for option in options:
            fo[option] = fetch_option[option]

        request = {
            "method": method_name,
            "params": [
                self.token,
                search_params,
                fo
            ],
        }
        return request

    def get_terms(self, vocabulary=None):
        """ Returns information about vocabulary, including its controlled vocabulary
        """

        search_request = {}
        if vocabulary is not None:
            search_request = _gen_search_criteria({
                "vocabulary": "VocabularyTerm",
                "criteria": [{
                    "vocabulary": "Vocabulary",
                    "code": vocabulary
                }]
            })

        fetch_options = {
            "vocabulary": {"@type": "as.dto.vocabulary.fetchoptions.VocabularyFetchOptions"},
            "@type": "as.dto.vocabulary.fetchoptions.VocabularyTermFetchOptions"
        }

        request = {
            "method": "searchVocabularyTerms",
            "params": [self.token, search_request, fetch_options]
        }
        resp = self._post_request(self.as_v3, request)
        parse_jackson(resp)
        return Vocabulary(resp)

    def get_tags(self):
        """ Returns a DataFrame of all 
        """
        request = {
            "method": "searchTags",
            "params": [self.token, {}, {}]
        }
        resp = self._post_request(self.as_v3, request)
        parse_jackson(resp)
        objects = DataFrame(resp['objects'])
        objects['registrationDate'] = objects['registrationDate'].map(format_timestamp)
        return objects[['code', 'registrationDate']]

    def get_sample_types(self, type=None):
        """ Returns a list of all available sample types
        """
        return self._get_types_of(
            "searchSampleTypes",
            "Sample",
            type,
            ["generatedCodePrefix"]
        )

    def get_sample_type(self, type):
        try:
            return self._get_types_of(
                "searchSampleTypes",
                "Sample",
                type,
                ["generatedCodePrefix"]
            )
        except Exception:
            raise ValueError("no such sample type: {}".format(type))

    def get_experiment_types(self, type=None):
        """ Returns a list of all available experiment types
        """
        return self._get_types_of(
            "searchExperimentTypes",
            "Experiment",
            type
        )

    def get_experiment_type(self, type):
        try:
            return self._get_types_of(
                "searchExperimentTypes",
                "Experiment",
                type
            )
        except Exception:
            raise ValueError("No such experiment type: {}".format(type))

    def get_material_types(self, type=None):
        """ Returns a list of all available material types
        """
        return self._get_types_of("searchMaterialTypes", "Material", type)

    def get_material_type(self, type):
        try:
            return self._get_types_of("searchMaterialTypes", "Material", type)
        except Exception:
            raise ValueError("No such material type: {}".format(type))

    def get_dataset_types(self, type=None):
        """ Returns a list (DataFrame object) of all currently available dataset types
        """
        return self._get_types_of("searchDataSetTypes", "DataSet", type, ['kind'])

    def get_dataset_type(self, type):
        try:
            return self._get_types_of("searchDataSetTypes", "DataSet", type, ['kind'])
        except Exception:
            raise ValueError("No such dataSet type: {}".format(type))

    def _get_types_of(self, method_name, entity, type_name=None, additional_attributes=None):
        """ Returns a list of all available types of an entity.
        If the name of the entity-type is given, it returns a PropertyAssignments object
        """
        if additional_attributes is None:
            additional_attributes = []

        attributes = ['code', 'description'] + additional_attributes + ['modificationDate']

        search_request = {}
        fetch_options = {}

        if type_name is not None:
            search_request = _gen_search_criteria({
                entity.lower(): entity + "Type",
                "operator": "AND",
                "code": type_name
            })

            fetch_options = {
                "@type": "as.dto.{}.fetchoptions.{}TypeFetchOptions".format(
                    entity.lower(), entity
                )
            }
            fetch_options['propertyAssignments'] = fetch_option['propertyAssignments']
            attributes.append('propertyAssignments')

        request = {
            "method": method_name,
            "params": [self.token, search_request, fetch_options],
        }
        resp = self._post_request(self.as_v3, request)
        parse_jackson(resp)

        if type_name is not None and len(resp['objects']) == 1:
            return PropertyAssignments(self, resp['objects'][0])
        if len(resp['objects']) >= 1:
            types = DataFrame(resp['objects'])
            types['modificationDate'] = types['modificationDate'].map(format_timestamp)
            return Things(self, entity.lower() + '_type', types[attributes])
            return types[attributes]

        else:
            raise ValueError("Nothing found!")

    def is_session_active(self):
        """ checks whether a session is still active. Returns true or false.
        """
        return self.is_token_valid(self.token)

    def is_token_valid(self, token=None):
        """Check if the connection to openBIS is valid.
        This method is useful to check if a token is still valid or if it has timed out,
        requiring the user to login again.
        :return: Return True if the token is valid, False if it is not valid.
        """
        if token is None:
            token = self.token

        if token is None:
            return False

        request = {
            "method": "isSessionActive",
            "params": [token],
        }
        resp = self._post_request(self.as_v1, request)
        return resp

    def get_dataset(self, permid):
        """fetch a dataset and some metadata attached to it:
        - properties
        - sample
        - parents
        - children
        - containers
        - dataStore
        - physicalData
        - linkedData
        :return: a DataSet object
        """

        criteria = [{
            "permId": permid,
            "@type": "as.dto.dataset.id.DataSetPermId"
        }]

        fetchopts = {
            "parents": {"@type": "as.dto.dataset.fetchoptions.DataSetFetchOptions"},
            "children": {"@type": "as.dto.dataset.fetchoptions.DataSetFetchOptions"},
            "containers": {"@type": "as.dto.dataset.fetchoptions.DataSetFetchOptions"},
            "type": {"@type": "as.dto.dataset.fetchoptions.DataSetTypeFetchOptions"},
        }

        # 2017-04-05 CR Needed to remove the linkedData option as this does not seem to work in S251.
        # for option in ['tags', 'properties', 'dataStore', 'physicalData', 'linkedData',
        for option in ['tags', 'properties', 'dataStore', 'physicalData',
                       'experiment', 'sample']:
            fetchopts[option] = fetch_option[option]

        request = {
            "method": "getDataSets",
            "params": [self.token,
                       criteria,
                       fetchopts,
                       ],
        }

        resp = self._post_request(self.as_v3, request)
        if resp is None or len(resp) == 0:
            raise ValueError('no such dataset found: ' + permid)
        if resp is not None:
            for permid in resp:
                return DataSet(self, self.get_dataset_type(resp[permid]["type"]["code"]), resp[permid])

    def get_sample(self, sample_ident, only_data=False, withAttachments=False):
        """Retrieve metadata for the sample.
        Get metadata for the sample and any directly connected parents of the sample to allow access
        to the same information visible in the ELN UI. The metadata will be on the file system.
        :param sample_identifiers: A list of sample identifiers to retrieve.
        """

        fetchopts = {"type": {"@type": "as.dto.sample.fetchoptions.SampleTypeFetchOptions"}}

        search_request = search_request_for_identifier(sample_ident, 'sample')

        for option in ['tags', 'properties', 'attachments', 'space', 'experiment', 'registrator', 'dataSets']:
            fetchopts[option] = fetch_option[option]

        if withAttachments:
            fetchopts['attachments'] = fetch_option['attachmentsWithContent']

        # fetchopts["parents"]  = { "@type": "as.dto.sample.fetchoptions.SampleFetchOptions" }
        # fetchopts["children"] = { "@type": "as.dto.sample.fetchoptions.SampleFetchOptions" }

        sample_request = {
            "method": "getSamples",
            "params": [
                self.token,
                [search_request],
                fetchopts
            ],
        }

        resp = self._post_request(self.as_v3, sample_request)
        parse_jackson(resp)

        if resp is None or len(resp) == 0:
            raise ValueError('no such sample found: ' + sample_ident)
        else:
            for sample_ident in resp:
                if only_data:
                    return resp[sample_ident]
                else:
                    return Sample(self, self.get_sample_type(resp[sample_ident]["type"]["code"]), resp[sample_ident])

    def get_external_data_management_system(self, perm_id, only_data=False):
        """Retrieve metadata for the external data management system.
        :param perm_id: A permId for an external DMS.
        :param only_data: Return the result data as a hash-map, not an object.
        """

        request = {
            "method": "getExternalDataManagementSystems",
            "params": [
                self.token,
                [{
                    "@type": "as.dto.externaldms.id.ExternalDmsPermId",
                    "permId": perm_id
                }],
                {},
            ],
        }

        resp = self._post_request(self.as_v3, request)
        parse_jackson(resp)

        if resp is None or len(resp) == 0:
            raise ValueError('no such external DMS found: ' + perm_id)
        else:
            for ident in resp:
                if only_data:
                    return resp[ident]
                else:
                    return ExternalDMS(self, resp[ident])

    def new_space(self, name, description=None):
        """ Creates a new space in the openBIS instance.
        """
        request = {
            "method": "createSpaces",
            "params": [
                self.token,
                [{
                    "code": name,
                    "description": description,
                    "@type": "as.dto.space.create.SpaceCreation"
                }]
            ],
        }
        resp = self._post_request(self.as_v3, request)
        return self.get_space(name)

    def new_analysis(self, name, description=None, sample=None, dss_code=None, result_files=None,
                     notebook_files=None, parents=None):

        """ An analysis contains the Jupyter notebook file(s) and some result files.
            Technically this method involves uploading files to the session workspace
            and activating the dropbox aka dataset ingestion service "jupyter-uploader-api"
        """

        if dss_code is None:
            dss_code = self.get_datastores()['code'][0]

        # if a sample identifier was given, use it as a string.
        # if a sample object was given, take its identifier
        sampleId = self.sample_to_sample_id(sample)

        parentIds = []
        if parents is not None:
            if not isinstance(parents, list):
                parants = [parents]
            for parent in parents:
                parentIds.append(parent.permId)

        datastore_url = self._get_dss_url(dss_code)
        folder = time.strftime('%Y-%m-%d_%H-%M-%S')

        # upload the files
        data_sets = []
        if notebook_files is not None:
            notebooks_folder = os.path.join(folder, 'notebook_files')
            self.upload_files(
                datastore_url=datastore_url,
                files=notebook_files,
                folder=notebooks_folder,
                wait_until_finished=True
            )
            data_sets.append({
                "dataSetType": "JUPYTER_NOTEBOOk",
                "sessionWorkspaceFolder": notebooks_folder,
                "fileNames": notebook_files,
                "properties": {}
            })
        if result_files is not None:
            results_folder = os.path.join(folder, 'result_files')
            self.upload_files(
                datastore_url=datastore_url,
                files=result_files,
                folder=results_folder,
                wait_until_finished=True
            )
            data_sets.append({
                "dataSetType": "JUPYTER_RESULT",
                "sessionWorkspaceFolder": results_folder,
                "fileNames": result_files,
                "properties": {}
            })

        # register the files in openBIS
        request = {
            "method": "createReportFromAggregationService",
            "params": [
                self.token,
                dss_code,
                DROPBOX_PLUGIN,
                {
                    "sample": {"identifier": sampleId['identifier']},
                    "sampleId": sampleId,
                    "parentIds": parentIds,
                    "containers": [{
                        "dataSetType": "JUPYTER_CONTAINER",
                        "properties": {
                            "NAME": name,
                            "DESCRIPTION": description
                        }
                    }],
                    "dataSets": data_sets,
                }
            ],
        }

        resp = self._post_request(self.reg_v1, request)
        try:
            if resp['rows'][0][0]['value'] == 'OK':
                return resp['rows'][0][1]['value']
        except:
            return resp

    def new_git_data_set(self, data_set_type, path, commit_id, dms, sample=None, properties={},
                         dss_code=None, parents=None, data_set_code=None):
        """ Create a link data set.
        :param data_set_type: The type of the data set
        :param data_set_type: The type of the data set
        :param path: The path to the git repository
        :param commit_id: The git commit id
        :param dms: An external data managment system object or external_dms_id
        :param sample: A sample object or sample id.
        :param dss_code: Code for the DSS -- defaults to the first dss if none is supplied.
        :param properties: Properties for the data set.
        :param parents: Parents for the data set.
        :param data_set_code: A data set code -- used if provided, otherwise generated on the server
        :return: A DataSet object
        """
        return pbds.GitDataSetCreation(self, data_set_type, path, commit_id, dms, sample,
                                       properties, dss_code, parents, data_set_code).new_git_data_set()

    @staticmethod
    def sample_to_sample_id(sample):
        """Take sample which may be a string or object and return an identifier for it."""
        sampleId = None
        if isinstance(sample, str):
            if (is_identifier(sample)):
                sampleId = {
                    "identifier": sample,
                    "@type": "as.dto.sample.id.SampleIdentifier"
                }
            else:
                sampleId = {
                    "permId": sample,
                    "@type": "as.dto.sample.id.SamplePermId"
                }
        else:
            sampleId = {
                "identifier": sample.identifier,
                "@type": "as.dto.sample.id.SampleIdentifier"
            }
        return sampleId

    @staticmethod
    def data_set_to_data_set_id(data_set):
        if isinstance(data_set, str):
            code = data_set
        else:
            code = data_set.permId
        return {
            "permId": code,
            "@type": "as.dto.dataset.id.DataSetPermId"
        }

    def external_data_managment_system_to_dms_id(self, dms):
        if isinstance(dms, str):
            dms_id = {
                "permId": dms,
                "@type": "as.dto.externaldms.id.ExternalDmsPermId"
            }
        else:
            dms_id = {
                "identifier": dms.code,
                "@type": "as.dto.sample.id.SampleIdentifier"
            }
        return dms_id

    def new_sample(self, type, props=None, **kwargs):
        """ Creates a new sample of a given sample type.
        """
        return Sample(self, self.get_sample_type(type), None, props, **kwargs)

    def new_dataset(self, type, props=None, **kwargs):
        """ Creates a new dataset of a given sample type.
        """
        return DataSet(self, self.get_dataset_type(type.upper()), None, props, **kwargs)

    def _get_dss_url(self, dss_code=None):
        """ internal method to get the downloadURL of a datastore.
        """
        dss = self.get_datastores()
        if dss_code is None:
            return dss['downloadUrl'][0]
        else:
            return dss[dss['code'] == dss_code]['downloadUrl'][0]

    def upload_files(self, datastore_url=None, files=None, folder=None, wait_until_finished=False):

        if datastore_url is None:
            datastore_url = self._get_dss_url()

        if files is None:
            raise ValueError("Please provide a filename.")

        if folder is None:
            # create a unique foldername
            folder = time.strftime('%Y-%m-%d_%H-%M-%S')

        if isinstance(files, str):
            files = [files]

        self.files = files
        self.startByte = 0
        self.endByte = 0

        # define a queue to handle the upload threads
        queue = DataSetUploadQueue()

        real_files = []
        for filename in files:
            if os.path.isdir(filename):
                real_files.extend(
                    [os.path.join(dp, f) for dp, dn, fn in os.walk(os.path.expanduser(filename)) for f in fn])
            else:
                real_files.append(os.path.join(filename))

        # compose the upload-URL and put URL and filename in the upload queue 
        for filename in real_files:
            file_in_wsp = os.path.join(folder, filename)
            self.files_in_wsp.append(file_in_wsp)
            upload_url = (
                datastore_url + '/session_workspace_file_upload'
                + '?filename=' + os.path.join(folder, filename)
                + '&id=1'
                + '&startByte=0&endByte=0'
                + '&sessionID=' + self.token
            )
            queue.put([upload_url, filename, self.verify_certificates])

        # wait until all files have uploaded
        if wait_until_finished:
            queue.join()

        # return files with full path in session workspace
        return self.files_in_wsp


class DataSetUploadQueue():
    def __init__(self, workers=20):
        # maximum files to be uploaded at once
        self.upload_queue = Queue()

        # define number of threads and start them
        for t in range(workers):
            t = Thread(target=self.upload_file)
            t.daemon = True
            t.start()

    def put(self, things):
        """ expects a list [url, filename] which is put into the upload queue
        """
        self.upload_queue.put(things)

    def join(self):
        """ needs to be called if you want to wait for all uploads to be finished
        """
        self.upload_queue.join()

    def upload_file(self):
        while True:
            # get the next item in the queue
            upload_url, filename, verify_certificates = self.upload_queue.get()

            filesize = os.path.getsize(filename)

            # upload the file to our DSS session workspace
            with open(filename, 'rb') as f:
                resp = requests.post(upload_url, data=f, verify=verify_certificates)
                resp.raise_for_status()
                data = resp.json()
                assert filesize == int(data['size'])

            # Tell the queue that we are done
            self.upload_queue.task_done()


class DataSetDownloadQueue():
    def __init__(self, workers=20):
        # maximum files to be downloaded at once
        self.download_queue = Queue()

        # define number of threads
        for t in range(workers):
            t = Thread(target=self.download_file)
            t.daemon = True
            t.start()

    def put(self, things):
        """ expects a list [url, filename] which is put into the download queue
        """
        self.download_queue.put(things)

    def join(self):
        """ needs to be called if you want to wait for all downloads to be finished
        """
        self.download_queue.join()

    def download_file(self):
        while True:
            url, filename, file_size, verify_certificates = self.download_queue.get()
            # create the necessary directory structure if they don't exist yet
            os.makedirs(os.path.dirname(filename), exist_ok=True)

            # request the file in streaming mode
            r = requests.get(url, stream=True, verify=verify_certificates)
            with open(filename, 'wb') as f:
                for chunk in r.iter_content(chunk_size=1024):
                    if chunk:  # filter out keep-alive new chunks
                        f.write(chunk)

            assert os.path.getsize(filename) == int(file_size)
            self.download_queue.task_done()


class OpenBisObject():
    def __init__(self, openbis_obj, type, data=None, props=None, **kwargs):
        self.__dict__['openbis'] = openbis_obj
        self.__dict__['type'] = type
        self.__dict__['p'] = PropertyHolder(openbis_obj, type)
        self.__dict__['a'] = AttrHolder(openbis_obj, 'DataSet', type)

        # existing OpenBIS object
        if data is not None:
            self._set_data(data)

        if props is not None:
            for key in props:
                setattr(self.p, key, props[key])

        if kwargs is not None:
            for key in kwargs:
                setattr(self, key, kwargs[key])

    def __eq__(self, other):
        return str(self) == str(other)

    def __ne__(self, other):
        return str(self) != str(other)

    def _set_data(self, data):
        # assign the attribute data to self.a by calling it
        # (invoking the AttrHolder.__call__ function)
        self.a(data)
        self.__dict__['data'] = data

        # put the properties in the self.p namespace (without checking them)
        for key, value in data['properties'].items():
            self.p.__dict__[key.lower()] = value