Fix pickle deserialization of ExperimentData

qiskit_experiments/framework/experiment_data.py

@@ -2542,6 +2542,7 @@ def __setstate__(self, state):
         self._job_futures = ThreadSafeOrderedDict()
         self._analysis_futures = ThreadSafeOrderedDict()
         self._analysis_executor = futures.ThreadPoolExecutor(max_workers=1)
+        self._monitor_executor = futures.ThreadPoolExecutor()
 
     def __str__(self):
         line = 51 * "-"

releasenotes/notes/exp-data-pickle-61511b6e926e3198.yaml

@@ -0,0 +1,9 @@
+---
+fixes:
+  - |
+    Fixed :mod:`pickle` deserialization of :class:`.ExperimentData` objects.
+    Previously, :class:`.ExperimentData` objects could serialized and
+    deserialized using Python's ``pickle`` module, but deserialized objects
+    were not completely restored and an exception would be raised when doing
+    some operations like running analysis on the restored object. See `#1326
+    <https://github.com/Qiskit-Extensions/qiskit-experiments/pull/1326/files>`__.

test/base.py

@@ -143,6 +143,7 @@ def assertEqualExtended(
             *,
             msg: Optional[str] = None,
             strict_type: bool = False,
+            **kwargs,
         ):
             """Extended equality assertion which covers Qiskit Experiments classes.
 
@@ -163,7 +164,7 @@ def assertEqualExtended(
             default_msg = f"{first} != {second}"
 
             self.assertTrue(
-                is_equivalent(first, second, strict_type=strict_type),
+                is_equivalent(first, second, strict_type=strict_type, **kwargs),
                 msg=msg or default_msg,
             )
 

test/extended_equality.py

@@ -42,11 +42,7 @@
 
 
 def is_equivalent(
-    data1: Any,
-    data2: Any,
-    *,
-    strict_type: bool = True,
-    numerical_precision: float = 1e-8,
+    data1: Any, data2: Any, *, strict_type: bool = True, numerical_precision: float = 1e-8, **kwargs
 ) -> bool:
     """Check if two input data are equivalent.
 
@@ -71,10 +67,7 @@ def is_equivalent(
     if strict_type and type(data1) is not type(data2):
         return False
     evaluated = _is_equivalent_dispatcher(
-        data1,
-        data2,
-        strict_type=strict_type,
-        numerical_precision=numerical_precision,
+        data1, data2, strict_type=strict_type, numerical_precision=numerical_precision, **kwargs
     )
     if not isinstance(evaluated, (bool, np.bool_)):
         # When either one of input is numpy array type, it may broadcast equality check
@@ -240,24 +233,28 @@ def _check_curvefit_results(
 def _check_service_analysis_results(
     data1: AnalysisResult,
     data2: AnalysisResult,
+    ignore_result_id: bool = False,
     **kwargs,
 ):
     """Check equality of AnalysisResult class which is payload for experiment service."""
+    attrs = [
+        "name",
+        "value",
+        "extra",
+        "device_components",
+        "experiment_id",
+        "chisq",
+        "quality",
+        "verified",
+        "tags",
+        "auto_save",
+        "source",
+    ]
+    if not ignore_result_id:
+        attrs.append("result_id")
+
     return _check_all_attributes(
-        attrs=[
-            "name",
-            "value",
-            "extra",
-            "device_components",
-            "result_id",
-            "experiment_id",
-            "chisq",
-            "quality",
-            "verified",
-            "tags",
-            "auto_save",
-            "source",
-        ],
+        attrs,
         data1=data1,
         data2=data2,
         **kwargs,
@@ -292,12 +289,25 @@ def _check_dataframes(
 def _check_result_table(
     data1: AnalysisResultTable,
     data2: AnalysisResultTable,
+    ignore_result_id: bool = False,
     **kwargs,
 ):
     """Check equality of data frame which may involve Qiskit Experiments class value."""
+    table1 = data1.copy().to_dict(orient="index")
+    table2 = data2.copy().to_dict(orient="index")
+    for table in (table1, table2):
+        for result in table.values():
+            result.pop("created_time")
+            if ignore_result_id:
+                result.pop("result_id")
+    if ignore_result_id:
+        # Keys of the dict are based on the result ids so they must be ignored
+        # as well
+        table1 = list(table1.values())
+        table2 = list(table2.values())
     return is_equivalent(
-        data1.copy().to_dict(orient="index"),
-        data2.copy().to_dict(orient="index"),
+        table1,
+        table2,
         **kwargs,
     )
 

test/framework/test_framework.py

@@ -12,6 +12,7 @@
 
 """Tests for base experiment framework."""
 
+import pickle
 from test.fake_experiment import FakeExperiment, FakeAnalysis
 from test.base import QiskitExperimentsTestCase
 from itertools import product
@@ -116,6 +117,17 @@ def circuits(self):
                 num_jobs += 1
         self.assertEqual(len(job_ids), num_jobs)
 
+    def test_run_analysis_experiment_data_pickle_roundtrip(self):
+        """Test running analysis on ExperimentData after pickle roundtrip"""
+        analysis = FakeAnalysis()
+        expdata1 = analysis.run(ExperimentData(), seed=54321)
+        self.assertExperimentDone(expdata1)
+
+        expdata2 = pickle.loads(pickle.dumps(expdata1))
+        expdata2 = analysis.run(expdata2, replace_results=True, seed=54321)
+        self.assertExperimentDone(expdata2)
+        self.assertEqualExtended(expdata1, expdata2, ignore_result_id=True)
+
     def test_analysis_replace_results_true(self):
         """Test running analysis with replace_results=True"""
         analysis = FakeAnalysis()