From 8d635a8519c2630ebb583afe92eba8995ba24b89 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Elena=20Pe=C3=B1a=20Tapia?=
 <57907331+ElePT@users.noreply.github.com>
Date: Wed, 31 Jul 2024 18:44:35 +0200
Subject: [PATCH] Revert base class change for Sampler and Estimator V1
 implementations to avoid breaking instance checks. (#12871)

(cherry picked from commit 919cfd3baf8e02c21ca26074e94191cedf98b5d8)
---
 qiskit/primitives/backend_estimator.py | 15 ++++++++-------
 qiskit/primitives/backend_sampler.py   | 13 +++++++------
 qiskit/primitives/estimator.py         |  6 +++---
 qiskit/primitives/sampler.py           |  6 +++---
 4 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/qiskit/primitives/backend_estimator.py b/qiskit/primitives/backend_estimator.py
index f6a53c02ea9e..722ee900ceea 100644
--- a/qiskit/primitives/backend_estimator.py
+++ b/qiskit/primitives/backend_estimator.py
@@ -36,7 +36,7 @@
 )
 from qiskit.utils.deprecation import deprecate_func
 
-from .base import BaseEstimatorV1, EstimatorResult
+from .base import BaseEstimator, EstimatorResult
 from .primitive_job import PrimitiveJob
 from .utils import _circuit_key, _observable_key, init_observable
 
@@ -88,17 +88,18 @@ def _prepare_counts(results: list[Result]):
     return counts
 
 
-class BackendEstimator(BaseEstimatorV1[PrimitiveJob[EstimatorResult]]):
+class BackendEstimator(BaseEstimator[PrimitiveJob[EstimatorResult]]):
     """Evaluates expectation value using Pauli rotation gates.
 
     The :class:`~.BackendEstimator` class is a generic implementation of the
-    :class:`~.BaseEstimatorV1` interface that is used to wrap a :class:`~.BackendV2`
-    (or :class:`~.BackendV1`) object in the :class:`~.BaseEstimatorV1` API. It
+    :class:`~.BaseEstimator` (V1) interface that is used to wrap a :class:`~.BackendV2`
+    (or :class:`~.BackendV1`) object in the :class:`~.BaseEstimator` V1 API. It
     facilitates using backends that do not provide a native
-    :class:`~.BaseEstimatorV1` implementation in places that work with
-    :class:`~.BaseEstimatorV1`.
+    :class:`~.BaseEstimator` V1 implementation in places that work with
+    :class:`~.BaseEstimator` V1.
     However, if you're using a provider that has a native implementation of
-    :class:`~.BaseEstimatorV1` or :class:`~.BaseEstimatorV2`, it is a better
+    :class:`~.BaseEstimatorV1` ( :class:`~.BaseEstimator`) or
+    :class:`~.BaseEstimatorV2`, it is a better
     choice to leverage that native implementation as it will likely include
     additional optimizations and be a more efficient implementation.
     The generic nature of this class precludes doing any provider- or
diff --git a/qiskit/primitives/backend_sampler.py b/qiskit/primitives/backend_sampler.py
index 213b9701a556..905fa2371542 100644
--- a/qiskit/primitives/backend_sampler.py
+++ b/qiskit/primitives/backend_sampler.py
@@ -26,22 +26,23 @@
 from qiskit.utils.deprecation import deprecate_func
 
 from .backend_estimator import _prepare_counts, _run_circuits
-from .base import BaseSamplerV1, SamplerResult
+from .base import BaseSampler, SamplerResult
 from .primitive_job import PrimitiveJob
 from .utils import _circuit_key
 
 
-class BackendSampler(BaseSamplerV1[PrimitiveJob[SamplerResult]]):
-    """A :class:`~.BaseSamplerV1` implementation that provides a wrapper for
+class BackendSampler(BaseSampler[PrimitiveJob[SamplerResult]]):
+    """A :class:`~.BaseSampler` (V1) implementation that provides a wrapper for
     leveraging the Sampler V1 interface from any backend.
 
     This class provides a sampler interface from any backend and doesn't do
     any measurement mitigation, it just computes the probability distribution
     from the counts. It facilitates using backends that do not provide a
-    native :class:`~.BaseSamplerV1` implementation in places that work with
-    :class:`~.BaseSamplerV1`.
+    native :class:`~.BaseSampler` V1 implementation in places that work with
+    :class:`~.BaseSampler` V1.
     However, if you're using a provider that has a native implementation of
-    :class:`~.BaseSamplerV1` or :class:`~.BaseESamplerV2`, it is a better
+    :class:`~.BaseSamplerV1` ( :class:`~.BaseSampler`) or
+    :class:`~.BaseESamplerV2`, it is a better
     choice to leverage that native implementation as it will likely include
     additional optimizations and be a more efficient implementation.
     The generic nature of this class precludes doing any provider- or
diff --git a/qiskit/primitives/estimator.py b/qiskit/primitives/estimator.py
index 1ca1529852c3..6ae50ee7f0f5 100644
--- a/qiskit/primitives/estimator.py
+++ b/qiskit/primitives/estimator.py
@@ -26,7 +26,7 @@
 from qiskit.quantum_info.operators.base_operator import BaseOperator
 from qiskit.utils.deprecation import deprecate_func
 
-from .base import BaseEstimatorV1, EstimatorResult
+from .base import BaseEstimator, EstimatorResult
 from .primitive_job import PrimitiveJob
 from .utils import (
     _circuit_key,
@@ -36,9 +36,9 @@
 )
 
 
-class Estimator(BaseEstimatorV1[PrimitiveJob[EstimatorResult]]):
+class Estimator(BaseEstimator[PrimitiveJob[EstimatorResult]]):
     """
-    Reference implementation of :class:`BaseEstimatorV1`.
+    Reference implementation of :class:`BaseEstimator` (V1).
 
     :Run Options:
 
diff --git a/qiskit/primitives/sampler.py b/qiskit/primitives/sampler.py
index d93db4f04116..9155e50ad2ce 100644
--- a/qiskit/primitives/sampler.py
+++ b/qiskit/primitives/sampler.py
@@ -26,7 +26,7 @@
 from qiskit.result import QuasiDistribution
 from qiskit.utils.deprecation import deprecate_func
 
-from .base import BaseSamplerV1, SamplerResult
+from .base import BaseSampler, SamplerResult
 from .primitive_job import PrimitiveJob
 from .utils import (
     _circuit_key,
@@ -36,11 +36,11 @@
 )
 
 
-class Sampler(BaseSamplerV1[PrimitiveJob[SamplerResult]]):
+class Sampler(BaseSampler[PrimitiveJob[SamplerResult]]):
     """
     Sampler V1 class.
 
-    :class:`~Sampler` is a reference implementation of :class:`~BaseSamplerV1`.
+    :class:`~Sampler` is a reference implementation of :class:`~BaseSampler` (V1).
 
     :Run Options: