Add paging support for experiments and analysis results (#807)

* add limit

* mypy version

* fix no limit

* delete duplicate release note

* fix limit in test

(cherry picked from commit fc60113)

Makefile

@@ -17,7 +17,7 @@ lint:
 	pylint -rn qiskit/providers/ibmq test
 
 mypy:
-	mypy --module qiskit.providers.ibmq --show-error-codes --no-site-packages
+	mypy --module qiskit.providers.ibmq --show-error-codes --no-site-packages --python-version 3.7
 
 style:
 	pycodestyle qiskit test

qiskit/providers/ibmq/api/clients/experiment.py

@@ -46,27 +46,31 @@ def __init__(
 
     def experiments(
             self,
+            limit: Optional[int],
+            marker: Optional[str],
             backend_name: Optional[str],
             experiment_type: Optional[str] = None,
             start_time: Optional[List] = None,
             device_components: Optional[List[str]] = None,
             tags: Optional[List[str]] = None
-    ) -> List[Dict]:
+    ) -> Dict:
         """Retrieve experiments, with optional filtering.
 
         Args:
+            limit: Number of experiments to retrieve.
+            marker: Marker used to indicate where to start the next query.
             backend_name: Name of the backend.
             experiment_type: Experiment type.
             start_time: A list of timestamps used to filter by experiment start time.
             device_components: A list of device components used for filtering.
             tags: Tags used for filtering.
 
         Returns:
-            A list of experiments.
+            A list of experiments and the marker, if applicable.
         """
         resp = self.base_api.experiments(
-            backend_name, experiment_type, start_time, device_components, tags)
-        return resp['experiments']
+            limit, marker, backend_name, experiment_type, start_time, device_components, tags)
+        return resp
 
     def experiment_get(self, experiment_id: str) -> Dict:
         """Get a specific experiment.
@@ -180,27 +184,32 @@ def experiment_devices(self) -> List:
 
     def analysis_results(
             self,
+            limit: Optional[int],
+            marker: Optional[str],
             backend_name: Optional[str] = None,
             device_components: Optional[List[str]] = None,
             experiment_uuid: Optional[str] = None,
             result_type: Optional[str] = None,
             quality: Optional[List[str]] = None
-    ) -> List[Dict]:
+    ) -> Dict:
         """Return a list of analysis results.
 
         Args:
+            limit: Number of analysis results to retrieve.
+            marker: Marker used to indicate where to start the next query.
             backend_name: Name of the backend.
             device_components: A list of device components used for filtering.
             experiment_uuid: Experiment UUID used for filtering.
             result_type: Analysis result type used for filtering.
             quality: Quality value used for filtering.
 
         Returns:
-            A list of analysis results.
+            A list of analysis results and the marker, if applicable.
         """
         resp = self.base_api.analysis_results(
-            backend_name, device_components, experiment_uuid, result_type, quality)
-        return resp['analysis_results']
+            limit, marker, backend_name, device_components, experiment_uuid,
+            result_type, quality)
+        return resp
 
     def analysis_result_upload(self, result: Dict) -> Dict:
         """Upload an analysis result.

qiskit/providers/ibmq/api/rest/root.py

@@ -150,6 +150,8 @@ def reservations(self) -> List:
 
     def experiments(
             self,
+            limit: Optional[int],
+            marker: Optional[str],
             backend_name: Optional[str] = None,
             experiment_type: Optional[str] = None,
             start_time: Optional[List] = None,
@@ -159,6 +161,8 @@ def experiments(
         """Return experiment data.
 
         Args:
+            limit: Number of experiments to retrieve.
+            marker: Marker used to indicate where to start the next query.
             backend_name: Name of the backend.
             experiment_type: Experiment type.
             start_time: A list of timestamps used to filter by experiment start time.
@@ -180,6 +184,10 @@ def experiments(
             params['device_components'] = device_components
         if tags:
             params['tags'] = tags
+        if limit:
+            params['limit'] = limit
+        if marker:
+            params['marker'] = marker
         return self.session.get(url, params=params).json()
 
     def experiment_devices(self) -> Dict:
@@ -207,6 +215,8 @@ def experiment_upload(self, experiment: Dict) -> Dict:
 
     def analysis_results(
             self,
+            limit: Optional[int],
+            marker: Optional[str],
             backend_name: Optional[str] = None,
             device_components: Optional[List[str]] = None,
             experiment_uuid: Optional[str] = None,
@@ -216,6 +226,8 @@ def analysis_results(
         """Return all analysis results.
 
         Args:
+            limit: Number of analysis results to retrieve.
+            marker: Marker used to indicate where to start the next query.
             backend_name: Name of the backend.
             device_components: A list of device components used for filtering.
             experiment_uuid: Experiment UUID used for filtering.
@@ -237,6 +249,10 @@ def analysis_results(
             params['quality'] = quality
         if result_type:
             params['type'] = result_type
+        if limit:
+            params['limit'] = limit
+        if marker:
+            params['marker'] = marker
         return self.session.get(url, params=params).json()
 
     def analysis_result_upload(self, result: Dict) -> Dict:

qiskit/providers/ibmq/experiment/experiment.py

@@ -90,6 +90,7 @@ def __init__(
         self._updated_datetime = None
 
         self._api_client = provider.experiment._api_client  # type: ignore[has-type]
+        self._provider = provider
 
     def update_from_remote_data(self, remote_data: Dict) -> None:
         """Update the attributes of this instance using remote data.
@@ -184,10 +185,8 @@ def analysis_results(self) -> List:
         """Return analysis results associated with this experiment."""
         if self._analysis_results is None:
             try:
-                response = self._api_client.analysis_results(experiment_uuid=self.uuid)
-                self._analysis_results = []
-                for result in response:
-                    self._analysis_results.append(AnalysisResult.from_remote_data(result))
+                self._analysis_results = self._provider.experiment.analysis_results(
+                    experiment_id=self.uuid, limit=None)
             except RequestsApiError as api_err:
                 logger.warning("Unable to retrieve analysis results for this experiment: %s",
                                str(api_err))

qiskit/providers/ibmq/experiment/experimentservice.py

@@ -99,6 +99,7 @@ def backends(self) -> List[Dict]:
 
     def experiments(
             self,
+            limit: Optional[int] = 10,
             backend_name: Optional[str] = None,
             type: Optional[str] = None,  # pylint: disable=redefined-builtin
             start_datetime: Optional[datetime] = None,
@@ -110,6 +111,7 @@ def experiments(
         """Retrieve all experiments, with optional filtering.
 
         Args:
+            limit: Number of experiments to retrieve. ``None`` indicates no limit.
             backend_name: Backend name used for filtering.
             type: Experiment type used for filtering.
             start_datetime: Filter by the given start timestamp, in local time. This is used to
@@ -133,8 +135,11 @@ def experiments(
             A list of experiments.
 
         Raises:
-            ValueError: If an invalid `tags_operator` value is specified.
+            ValueError: If an invalid parameter value is specified.
         """
+        if limit is not None and (not isinstance(limit, int) or limit <= 0):  # type: ignore
+            raise ValueError(f"{limit} is not a valid `limit`, which has to be a positive integer.")
+
         start_time_filters = []
         if start_datetime:
             st_filter = 'ge:{}'.format(local_to_utc_str(start_datetime))
@@ -153,11 +158,19 @@ def experiments(
                 raise ValueError('{} is not a valid `tags_operator`. Valid values are '
                                  '"AND" and "OR".'.format(tags_operator))
 
-        raw_data = self._api_client.experiments(
-            backend_name, type, start_time_filters, device_components, tags_filter)
         experiments = []
-        for exp in raw_data:
-            experiments.append(Experiment.from_remote_data(self._provider, exp))
+        marker = None
+        while limit is None or limit > 0:
+            raw_data = self._api_client.experiments(
+                limit, marker, backend_name, type, start_time_filters,
+                device_components, tags_filter)
+            marker = raw_data.get('marker')
+            for exp in raw_data['experiments']:
+                experiments.append(Experiment.from_remote_data(self._provider, exp))
+            if limit:
+                limit -= len(raw_data['experiments'])
+            if not marker:  # No more experiments to return.
+                break
         return experiments
 
     def upload_experiment(self, experiment: Experiment) -> None:
@@ -250,6 +263,7 @@ def delete_experiment(self, experiment: Union[Experiment, str]) -> Optional[Expe
 
     def analysis_results(
             self,
+            limit: Optional[int] = 10,
             backend_name: Optional[str] = None,
             device_components: Optional[List[str]] = None,
             experiment_id: Optional[str] = None,
@@ -259,6 +273,7 @@ def analysis_results(
         """Retrieve all analysis results, with optional filtering.
 
         Args:
+            limit: Number of analysis results to retrieve.
             backend_name: Backend name used for filtering.
             device_components: Filter by device components. An analysis result's
                 device components must match this list exactly for it to be included.
@@ -274,20 +289,34 @@ def analysis_results(
 
         Returns:
             A list of analysis results.
+
+        Raises:
+            ValueError: If an invalid parameter value is specified.
         """
+        if limit is not None and (not isinstance(limit, int) or limit <= 0):  # type: ignore
+            raise ValueError(f"{limit} is not a valid `limit`, which has to be a positive integer.")
+
         qualit_list = []
         if quality:
             for op, qual in quality:
                 if isinstance(qual, ResultQuality):
                     qual = qual.value
                 qual_str = qual if op == 'eq' else "{}:{}".format(op, qual)
                 qualit_list.append(qual_str)
-        response = self._api_client.analysis_results(
-            backend_name=backend_name, device_components=device_components,
-            experiment_uuid=experiment_id, result_type=result_type, quality=qualit_list)
         results = []
-        for result in response:
-            results.append(AnalysisResult.from_remote_data(result))
+        marker = None
+        while limit is None or limit > 0:
+            raw_data = self._api_client.analysis_results(
+                limit=limit, marker=marker,
+                backend_name=backend_name, device_components=device_components,
+                experiment_uuid=experiment_id, result_type=result_type, quality=qualit_list)
+            marker = raw_data.get('marker')
+            for result in raw_data['analysis_results']:
+                results.append(AnalysisResult.from_remote_data(result))
+            if limit:
+                limit -= len(raw_data['analysis_results'])
+            if not marker:  # No more experiments to return.
+                break
         return results
 
     def upload_analysis_result(self, result: AnalysisResult) -> None:

releasenotes/notes/experiments-limit-c7805ef972b7b4c1.yaml

@@ -0,0 +1,15 @@
+---
+features:
+  - |
+    Methods
+    :meth:`qiskit.providers.ibmq.experiment.ExperimentService.experiments` and
+    :meth"`qiskit.providers.ibmq.experiment.ExperimentService.analysis_results`
+    now support a ``limit`` parameter that allows you to limit the number of
+    experiments and analysis results returned.
+upgrade:
+  - |
+    A new parameter, ``limit`` is now the first parameter for both
+    :meth:`qiskit.providers.ibmq.experiment.ExperimentService.experiments` and
+    :meth"`qiskit.providers.ibmq.experiment.ExperimentService.analysis_results`
+    methods. This ``limit`` has a default value of 10, meaning by deafult only
+    10 experiments and analysis results will be returned.