Add QPY serialization for PauliEvolutionGate

qiskit/circuit/qpy_serialization.py

@@ -115,7 +115,7 @@
 set and that name prefix it will error. If it's of type ``'p'`` the data payload is defined
 as follows:
 
-.. pauli_evo_qpy:
+.. _pauli_evo_qpy:
 
 PAULI_EVOLUTION
 ---------------
@@ -133,7 +133,7 @@
     }
 
 This is immediately followed by ``operator_count`` elements defined by the :ref:`pauli_sum_op`
-payload.  Following that we have `time_size`` bytes representing the ``time`` attribute. If
+payload.  Following that we have ``time_size`` bytes representing the ``time`` attribute. If
 ``standalone_op`` is ``True`` then there must only be a single operator. The
 encoding of these bytes is determined by the value of ``time_type``. Possible values of
 ``time_type`` are ``'f'``, ``'p'``, and ``'e'``. If ``time_type`` is ``'f'`` it's a double,
@@ -143,15 +143,15 @@
 Following that is ``synthesis_size`` bytes which is a utf8 encoded json payload representing
 the :class:`.EvolutionSynthesis` class used by the gate.
 
-.. pauli_sum_op
+.. _pauli_sum_op:
 
 SPARSE_PAULI_OP_LIST_ELEM
 -------------------------
 
-This represents an instance of :class:`~qiskit.opflow.PauliSumOp`.
+This represents an instance of :class:`.PauliSumOp`.
 
 
-.. code-block: c
+.. code-block:: c
 
     struct {
         uint32_t pauli_op_size;
@@ -273,7 +273,7 @@
 ``qr`` would have ``standalone`` set to ``False``.
 
 
-.. custom_definition:
+.. _custom_definition:
 
 CUSTOM_DEFINITIONS
 ------------------
@@ -381,7 +381,7 @@ class if it's defined in Qiskit. Otherwise it falls back to the custom
 (see below), and ``'n'`` represents an object from numpy (either an ``ndarray``
 or a numpy type) which means the data is .npy format [#f2]_ data.
 
-.. param_struct:
+.. _param_struct:
 
 PARAMETER
 ---------
@@ -589,7 +589,7 @@ class if it's defined in Qiskit. Otherwise it falls back to the custom
 COMPLEX_SIZE = struct.calcsize(COMPLEX_PACK)
 # Pauli Evolution Gate
 PAULI_EVOLUTION_DEF = namedtuple(
-    "PAULI_EVOLUTION_DEF", ["operator_size", "time_type", "time_size", "synth_method_size"]
+    "PAULI_EVOLUTION_DEF", ["operator_size", "standalone_op", "time_type", "time_size", "synth_method_size"]
 )
 PAULI_EVOLUTION_DEF_PACK = "!Q?1cQQ"
 PAULI_EVOLUTION_DEF_SIZE = struct.calcsize(PAULI_EVOLUTION_DEF_PACK)
@@ -860,9 +860,9 @@ def _read_custom_instructions(file_obj, version):
             definition_circuit = None
             if has_custom_definition:
                 definition_buffer = io.BytesIO(file_obj.read(size))
-                if version < 3 or not name.startswith(r"###PauliEvolutionGate"):
+                if version < 3 or not name.startswith(r"###PauliEvolutionGate_"):
                     definition_circuit = _read_circuit(definition_buffer, version)
-                elif name.startswith(r"###PauliEvolutionGate"):
+                elif name.startswith(r"###PauliEvolutionGate_"):
                     definition_circuit = _read_pauli_evolution_gate(definition_buffer)
             custom_instructions[name] = (type_str, num_qubits, num_clbits, definition_circuit)
     return custom_instructions
@@ -926,7 +926,7 @@ def _write_instruction(file_obj, instruction_tuple, custom_instructions, index_m
         )
         or gate_class_name == "Gate"
         or gate_class_name == "Instruction"
-        or isinstance(instruction_tuple[0], (library.BlueprintCircuit))
+        or isinstance(instruction_tuple[0], library.BlueprintCircuit)
     ):
         if instruction_tuple[0].name not in custom_instructions:
             custom_instructions[instruction_tuple[0].name] = instruction_tuple[0]
@@ -1033,32 +1033,32 @@ def _write_pauli_evolution_gate(file_obj, evolution_gate):
     num_operators = len(operator_list)
     pauli_data_buf = io.BytesIO()
     for operator in operator_list:
-        element_buf = io.BytesIO()
-        buf = io.BytesIO()
-        pauli_list = operator.to_list(array=True)
-        np.save(buf, pauli_list)
-        data = buf.getvalue()
-        element_metadata = struct.pack(SPARSE_PAULI_OP_LIST_ELEM_PACK, len(data))
-        element_buf.write(element_metadata)
-        element_buf.write(data)
-        pauli_data_buf.write(element_buf.getvalue())
+        with io.BytesIO() as element_buf:
+            with io.BytesIO() as buf:
+                pauli_list = operator.to_list(array=True)
+                np.save(buf, pauli_list)
+                data = buf.getvalue()
+            element_metadata = struct.pack(SPARSE_PAULI_OP_LIST_ELEM_PACK, len(data))
+            element_buf.write(element_metadata)
+            element_buf.write(data)
+            pauli_data_buf.write(element_buf.getvalue())
     time = evolution_gate.time
     if isinstance(time, float):
         time_type = b"f"
         time_data = struct.pack("!d", time)
         time_size = struct.calcsize("!d")
     elif isinstance(time, Parameter):
         time_type = b"p"
-        buf = io.BytesIO()
-        _write_parameter(buf, time)
-        time_data = buf.getvalue()
-        time_size = len(time_data)
+        with io.BytesIO() as buf:
+            _write_parameter(buf, time)
+            time_data = buf.getvalue()
+            time_size = len(time_data)
     elif isinstance(time, ParameterExpression):
         time_type = b"e"
-        buf = io.BytesIO()
-        _write_parameter_expression(buf, time)
-        time_data = buf.getvalue()
-        time_size = len(time_data)
+        with io.BytesIO() as buf:
+            _write_parameter_expression(buf, time)
+            time_data = buf.getvalue()
+            time_size = len(time_data)
     else:
         raise TypeError(f"Invalid time type {time} for PauliEvolutionGate")
 
@@ -1071,6 +1071,7 @@ def _write_pauli_evolution_gate(file_obj, evolution_gate):
     )
     file_obj.write(pauli_evolution_raw)
     file_obj.write(pauli_data_buf.getvalue())
+    pauli_data_buf.close()
     file_obj.write(time_data)
     file_obj.write(synth_data)
 
@@ -1099,11 +1100,11 @@ def _read_pauli_evolution_gate(file_obj):
     if time_type == b"f":
         time = struct.unpack("!d", time_data)[0]
     elif time_type == b"p":
-        buf = io.BytesIO(time_data)
-        time = _read_parameter(buf)
+        with io.BytesIO(time_data) as buf:
+            time = _read_parameter(buf)
     elif time_type == b"e":
-        buf = io.BytesIO(time_data)
-        time = _read_parameter_expression(buf)
+        with io.BytesIO(time_data) as buf:
+           time = _read_parameter_expression(buf)
     synth_data = json.loads(file_obj.read(pauli_evolution_raw[4]))
     synthesis = getattr(evo_synth, synth_data["class"])(**synth_data["settings"])
     return_gate = library.PauliEvolutionGate(pauli_op, time=time, synthesis=synthesis)

qiskit/test/base.py

@@ -62,7 +62,6 @@ class BaseTestCase(testtools.TestCase):
         assertRaises = unittest.TestCase.assertRaises
         assertEqual = unittest.TestCase.assertEqual
 
-
 else:
 
     class BaseTestCase(unittest.TestCase):

releasenotes/notes/fix-pauli-evolution-gate-bf85592f0f8f0ba7.yaml

@@ -17,8 +17,8 @@ fixes:
     available from :mod:`qiskit.synthesis` can be used with a
     :class:`~qiskit.circuit.library.PauliEvolutionGate` for qpy serialization.
 
-    To fix this the requires a new QPY format version, :ref:`version_3`, which
-    contains a representation of the
+    To fix this issue a new QPY format version, :ref:`version_3`, was required.
+    This new format version includes a representation of the
     :class:`~qiskit.circuit.library.PauliEvolutionGate` class which is
-    described in the `~qiskit.circuit.qpy_serialization` documentation at
+    described in the :mod:`~qiskit.circuit.qpy_serialization` documentation at
     :ref:`pauli_evo_qpy`.