Prepare for Qiskit 2.0 by addressing removed classes and methods

CONTRIBUTING.md

@@ -424,12 +424,11 @@ release notes.
 
 #### Adding deprecation warnings
 
-We use the deprecation wrappers in [Qiskit
-Utilities](https://docs.quantum.ibm.com/api/qiskit/utils) to add warnings:
+We use deprecation wrappers in `qiskit_experiments.framework.deprecation` to add warnings:
 
 ```python
 
-  from qiskit.utils.deprecation import deprecate_func
+  from qiskit_experiments.framework.deprecation import deprecate_func
 
   @deprecate_func(
       since="0.5",

docs/conf.py

@@ -211,9 +211,12 @@ def setup(app):
 # Should come up with better way to address this
 
 from qiskit_experiments.curve_analysis import ParameterRepr
+from qiskit_experiments.framework import MeasLevel, MeasReturnType
 
 
 def maybe_skip_member(app, what, name, obj, skip, options):
+    if skip:
+        return True
     skip_names = [
         "analysis",
         "set_run_options",
@@ -234,6 +237,11 @@ def maybe_skip_member(app, what, name, obj, skip, options):
         ParameterRepr.repr,
         ParameterRepr.unit,
     ]
+    if (
+        not name.isupper() and
+        (getattr(MeasLevel, name, None) == obj or getattr(MeasReturnType, name, None) == obj)
+    ):
+        return True
     if not skip:
         return (name in skip_names or obj in skip_members) and what == "attribute"
     return skip

docs/manuals/characterization/t1.rst

@@ -37,8 +37,7 @@ for qubit 0.
 .. jupyter-execute::
 
     import numpy as np
-    from qiskit.qobj.utils import MeasLevel
-    from qiskit_experiments.framework import ParallelExperiment
+    from qiskit_experiments.framework import MeasLevel, ParallelExperiment
     from qiskit_experiments.library import T1
     from qiskit_experiments.library.characterization.analysis.t1_analysis import T1KerneledAnalysis
 

docs/tutorials/custom_experiment.rst

@@ -601,7 +601,7 @@ perfect symmetrical results between :math:`|0000\rangle` and :math:`|1111\rangle
 
 .. jupyter-execute::
 
-    expdata_ideal = exp.run(AerSimulator(), shots=shots)
+    expdata_ideal = exp.run(backend_ideal, shots=shots)
     counts_ideal = expdata_ideal.analysis_results("counts").value
     print(counts_ideal)
 

docs/tutorials/getting_started.rst

@@ -297,7 +297,7 @@ supports can be set:
 
 .. jupyter-execute::
 
-  from qiskit.qobj.utils import MeasLevel
+  from qiskit_experiments.framework import MeasLevel
 
   exp.set_run_options(shots=1000,
                       meas_level=MeasLevel.CLASSIFIED)

qiskit_experiments/curve_analysis/utils.py

@@ -19,14 +19,14 @@
 import lmfit
 import numpy as np
 import pandas as pd
-from qiskit.utils.deprecation import deprecate_func
 from qiskit.utils import detach_prefix
 from uncertainties import UFloat, wrap as wrap_function
 from uncertainties import unumpy
 
 from qiskit_experiments.curve_analysis.curve_data import CurveFitResult
 from qiskit_experiments.exceptions import AnalysisError, QiskitError
 from qiskit_experiments.framework import AnalysisResultData
+from qiskit_experiments.framework.deprecation import deprecate_func
 
 
 UNUMPY_FUNCS = {fn: getattr(unumpy, fn) for fn in unumpy.__all__}

qiskit_experiments/data_processing/mitigation/local_readout_mitigator.py

@@ -15,6 +15,7 @@
 
 
 import math
+import warnings
 from typing import Optional, List, Tuple, Iterable, Callable, Union, Dict
 import numpy as np
 
@@ -53,6 +54,8 @@ def __init__(
         Raises:
             QiskitError: matrices sizes do not agree with number of qubits
         """
+        if assignment_matrices is None and backend is None:
+            raise QiskitError("Either assignment_matrices or backend must be provided.")
         if assignment_matrices is None:
             assignment_matrices = self._from_backend(backend, qubits)
         else:
@@ -293,7 +296,14 @@ def stddev_upper_bound(self, shots: int, qubits: List[int] = None):
 
     def _from_backend(self, backend, qubits):
         """Calculates amats from backend properties readout_error"""
-        backend_qubits = backend.properties().qubits
+        try:
+            backend_qubits = backend.properties().qubits
+        except AttributeError as exc:
+            raise QiskitError(
+                "Either assignment_matrices must be passed or a backend "
+                "supporting backend.properties().qubits"
+            ) from exc
+
         if qubits is not None:
             if any(qubit >= len(backend_qubits) for qubit in qubits):
                 raise QiskitError("The chosen backend does not contain the specified qubits.")
@@ -304,13 +314,20 @@ def _from_backend(self, backend, qubits):
         amats = np.zeros([num_qubits, 2, 2], dtype=float)
 
         for qubit_idx, qubit_prop in enumerate(backend_qubits):
+            props_to_find = {"prob_meas0_prep1", "prob_meas1_prep0"}
             for prop in qubit_prop:
                 if prop.name == "prob_meas0_prep1":
+                    props_to_find.discard(prop.name)
                     (amats[qubit_idx])[0, 1] = prop.value
                     (amats[qubit_idx])[1, 1] = 1 - prop.value
                 if prop.name == "prob_meas1_prep0":
+                    props_to_find.discard(prop.name)
                     (amats[qubit_idx])[1, 0] = prop.value
                     (amats[qubit_idx])[0, 0] = 1 - prop.value
+            if props_to_find:
+                warnings.warn(
+                    f"Expected readout error properties were missing: {','.join(props_to_find)}"
+                )
 
         return amats
 

qiskit_experiments/data_processing/nodes.py

@@ -23,7 +23,7 @@
 from uncertainties import unumpy as unp, ufloat
 
 from qiskit.result.postprocess import format_counts_memory
-from qiskit.utils import deprecate_func
+from qiskit_experiments.framework.deprecation import deprecate_func
 from qiskit_experiments.data_processing.data_action import DataAction, TrainableDataAction
 from qiskit_experiments.data_processing.exceptions import DataProcessorError
 from qiskit_experiments.data_processing.discriminator import BaseDiscriminator
@@ -921,6 +921,7 @@ class RestlessNode(DataAction, ABC):
             "processor on an experiment."
         ),
         package_name="qiskit-experiments",
+        stacklevel=3,
     )
     def __init__(
         self, validate: bool = True, memory_allocation: ShotOrder = ShotOrder.circuit_first

qiskit_experiments/data_processing/processor_library.py

@@ -14,9 +14,8 @@
 
 import warnings
 from typing import Union, Optional, List
-from qiskit.qobj.utils import MeasLevel, MeasReturnType
 
-from qiskit_experiments.framework import ExperimentData, Options
+from qiskit_experiments.framework import ExperimentData, MeasLevel, MeasReturnType, Options
 from qiskit_experiments.data_processing.exceptions import DataProcessorError
 from qiskit_experiments.data_processing.data_action import DataAction
 from qiskit_experiments.data_processing.data_processor import DataProcessor

qiskit_experiments/framework/__init__.py

@@ -99,6 +99,8 @@
     Job
     BaseJob
     ExtendedJob
+    MeasLevel
+    MeasReturnType
 
 .. _composite-experiment:
 
@@ -145,6 +147,17 @@
     FigureData,
     FigureType,
 )
+from .provider_interfaces import (
+    BaseJob,
+    BaseProvider,
+    ExtendedJob,
+    IBMProvider,
+    Job,
+    MeasLevel,
+    MeasReturnType,
+    Provider,
+)
+
 from .base_analysis import BaseAnalysis
 from .base_experiment import BaseExperiment
 from .backend_timing import BackendTiming
@@ -159,4 +172,3 @@
     CompositeAnalysis,
 )
 from .json import ExperimentEncoder, ExperimentDecoder
-from .provider_interfaces import BaseJob, BaseProvider, ExtendedJob, IBMProvider, Job, Provider

qiskit_experiments/framework/backend_data.py

@@ -12,12 +12,19 @@
 """
 Backend data access helper class
 
-Since `BackendV1` and `BackendV2` do not share the same interface, this
-class unifies data access for various data fields.
+This class was introduced to unify backend data access to either `BackendV1` and `BackendV2`
+objects, wrapped by an object of this class. With the removal of `BackendV1` in Qiskit 2.0,
+this class will not serve any useful purpose once support for Qiskit 1 is dropped.
+
+TODO: remove this class 
 """
+import os
+import sys
 import warnings
-from qiskit.providers.models import PulseBackendConfiguration  # pylint: disable=no-name-in-module
-from qiskit.providers import BackendV1, BackendV2
+
+from qiskit.providers import BackendV2
+
+import qiskit_experiments
 
 
 class BackendData:
@@ -27,22 +34,33 @@ def __init__(self, backend):
         """Inits the backend and verifies version"""
 
         self._backend = backend
-        self._v1 = isinstance(backend, BackendV1)
+        self._v1 = False
         self._v2 = isinstance(backend, BackendV2)
-
-        if self._v2:
-            with warnings.catch_warnings():
-                warnings.filterwarnings(
-                    "ignore", message=".*qiskit.qobj.pulse_qobj.*", category=DeprecationWarning
-                )
-                self._parse_additional_data()
-
-    def _parse_additional_data(self):
-        # data specific parsing not done yet in upstream qiskit
-        if hasattr(self._backend, "_conf_dict") and self._backend._conf_dict["open_pulse"]:
-            if "u_channel_lo" not in self._backend._conf_dict:
-                self._backend._conf_dict["u_channel_lo"] = []  # to avoid qiskit bug
-            self._pulse_conf = PulseBackendConfiguration.from_dict(self._backend._conf_dict)
+        if not self._v2:
+            try:
+                from qiskit.providers import BackendV1
+
+                self._v1 = isinstance(backend, BackendV1)
+
+                if self._v1:
+                    if sys.version_info[:2] >= (3, 12):
+                        kwargs = {
+                            "skip_file_prefixes": (os.path.dirname(qiskit_experiments.__file__),)
+                        }
+                    else:
+                        kwargs = {}
+                    warnings.warn(
+                        (
+                            "Support for BackendV1 with Qiskit Experiments is "
+                            "deprecated and will be removed in a future release. "
+                            "Please update to using BackendV2 backends."
+                        ),
+                        DeprecationWarning,
+                        stacklevel=2,
+                        **kwargs,
+                    )
+            except ImportError:
+                pass
 
     @property
     def name(self):

qiskit_experiments/framework/base_experiment.py

@@ -21,11 +21,10 @@
 from qiskit import transpile, QuantumCircuit
 from qiskit.providers import Job, Backend
 from qiskit.exceptions import QiskitError
-from qiskit.qobj.utils import MeasLevel
 from qiskit.providers.options import Options
 from qiskit.primitives.base import BaseSamplerV2
 from qiskit_ibm_runtime import SamplerV2 as Sampler
-from qiskit_experiments.framework import BackendData
+from qiskit_experiments.framework import BackendData, MeasLevel
 from qiskit_experiments.framework.store_init_args import StoreInitArgs
 from qiskit_experiments.framework.base_analysis import BaseAnalysis
 from qiskit_experiments.framework.experiment_data import ExperimentData