Fix input normalisation of transpile(initial_layout=...) (backport #11031)

qiskit/compiler/transpiler.py

@@ -503,10 +503,10 @@ def _parse_initial_layout(initial_layout):
         return initial_layout
     if isinstance(initial_layout, dict):
         return Layout(initial_layout)
+    initial_layout = list(initial_layout)
     if all(phys is None or isinstance(phys, Qubit) for phys in initial_layout):
         return Layout.from_qubit_list(initial_layout)
-    else:
-        return initial_layout
+    return initial_layout
 
 
 def _parse_instruction_durations(backend, inst_durations, dt, circuit):

releasenotes/notes/fix-input-normalization-of-transpile-initial-layout.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixed a regression in :func:`.transpile`, where an ``initial_layout`` given
+    as a :class:`range` object would no longer be treated as a valid input.
+    Fixed `#10544 <https://github.com/Qiskit/qiskit/issues/10554>`__.

test/python/transpiler/test_set_layout.py

@@ -0,0 +1,34 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2023
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+# pylint: disable=missing-function-docstring
+
+"""Tests the SetLayout pass"""
+
+from qiskit.compiler import transpile
+from qiskit.circuit import QuantumCircuit
+from qiskit.transpiler import CouplingMap
+from qiskit.test import QiskitTestCase
+
+
+class TestSetLayout(QiskitTestCase):
+    """Test the SetLayout pass."""
+
+    def test_initial_layout_consistency_for_range_and_list(self):
+        qc = QuantumCircuit(3)
+        qc.h(0)
+        qc.cx(0, 1)
+        qc.cx(0, 2)
+        cmap = CouplingMap.from_line(3, bidirectional=False)
+        tqc_1 = transpile(qc, coupling_map=cmap, initial_layout=range(3), seed_transpiler=42)
+        tqc_2 = transpile(qc, coupling_map=cmap, initial_layout=list(range(3)), seed_transpiler=42)
+        self.assertEqual(tqc_1.layout.initial_layout, tqc_2.layout.initial_layout)