Merge branch 'main' into sphinx-keep-going

qiskit/qpy/binary_io/circuits.py

@@ -240,7 +240,7 @@ def _read_instruction(file_obj, circuit, registers, custom_instructions, version
     if gate_name in {"IfElseOp", "WhileLoopOp"}:
         gate = gate_class(condition_tuple, *params)
     else:
-        if gate_name == "Initialize":
+        if gate_name in {"Initialize", "UCRXGate", "UCRYGate", "UCRZGate"}:
             gate = gate_class(params)
         else:
             if gate_name == "Barrier":

releasenotes/notes/ucr-gates-qpy-b8f6fb1e34fae258.yaml

@@ -0,0 +1,18 @@
+---
+fixes:
+  - |
+    Fixed an issue with QPY deserialization via the :func:`.qpy.load` function
+    of the :class:`~.UCRXGate`, :class:`~.UCRYGate`, and :class:`~.UCRZGate`.
+    Previously, a QPY file that contained any of these gates would error
+    when trying to load the file.
+    Fixed `#7847 <https://github.com/Qiskit/qiskit-terra/issues/7847>`__
+issues:
+  - |
+    QPY deserialization with the :func:`.qpy.load` function of a directly
+    instantiated :class:`~.UCPauliRotGate` object in a circuit will fail
+    because the rotation axis argument to the class isn't stored in a standard
+    place. To workaround this you can instead use the subclasses:
+    :class:`~.UCRXGate`, :class:`~.UCRYGate`, or :class:`~.UCRZGate` (based on
+    whether you're using a rotation axis of ``"X"``, ``"Y"``, or ``"Z"``
+    respectively) which embeds the rotation axis in the class constructor and
+    will work correctly in QPY.

test/python/circuit/test_circuit_load_from_qpy.py

@@ -941,3 +941,16 @@ def test_empty_tuple_param(self):
         qpy_file.seek(0)
         new_circuit = load(qpy_file)[0]
         self.assertEqual(qc, new_circuit)
+
+    def test_ucr_gates(self):
+        """Test qpy with UCRX, UCRY, and UCRZ gates."""
+        qc = QuantumCircuit(3)
+        qc.ucrz([0, 0, 0, -np.pi], [0, 1], 2)
+        qc.ucry([0, 0, 0, -np.pi], [0, 2], 1)
+        qc.ucrx([0, 0, 0, -np.pi], [2, 1], 0)
+        qc.measure_all()
+        qpy_file = io.BytesIO()
+        dump(qc, qpy_file)
+        qpy_file.seek(0)
+        new_circuit = load(qpy_file)[0]
+        self.assertEqual(qc.decompose().decompose(), new_circuit.decompose().decompose())