Add transpiler directory for pulse transforms

qiskit/transpiler/passes/__init__.py

@@ -88,6 +88,9 @@
    DynamicalDecoupling
    AlignMeasures
    ValidatePulseGates
+
+Transformation
+===============
    RZXCalibrationBuilder
    RZXCalibrationBuilderNoEcho
 
@@ -191,12 +194,14 @@
 from .scheduling import TimeUnitConversion
 from .scheduling import ALAPSchedule
 from .scheduling import ASAPSchedule
-from .scheduling import RZXCalibrationBuilder
 from .scheduling import RZXCalibrationBuilderNoEcho
 from .scheduling import DynamicalDecoupling
 from .scheduling import AlignMeasures
 from .scheduling import ValidatePulseGates
 
+# circuit transformation
+from .transformation import RZXCalibrationBuilder
+
 # additional utility passes
 from .utils import CheckMap
 from .utils import CheckCXDirection  # Deprecated

qiskit/transpiler/passes/scheduling/calibration_creators.py

@@ -12,6 +12,7 @@
 
 """Calibration creators."""
 
+import warnings
 import math
 from typing import List, Union
 from abc import abstractmethod
@@ -103,6 +104,13 @@ def __init__(self, backend: basebackend):
         self._config = backend.configuration()
         self._channel_map = backend.configuration().qubit_channel_mapping
 
+        warnings.warn(
+            "The scheduling.calibration_creators.py has been deprecated "
+            "and replaced by transformation.calibration_creators.py.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+
     def supported(self, node_op: DAGNode) -> bool:
         """
         Args:

qiskit/transpiler/passes/scheduling/rzx_templates.py

@@ -13,7 +13,7 @@
 """
 Convenience function to load RZXGate based templates.
 """
-
+import warnings
 from typing import List
 
 from qiskit.circuit.library.templates.rzx import rzx_zz1, rzx_zz2, rzx_zz3, rzx_yz, rzx_xz, rzx_cy
@@ -46,4 +46,10 @@ def rzx_templates(template_list: List[str] = None):
 
     rzx_dict = {"template_list": templates, "user_cost_dict": cost_dict}
 
+    warnings.warn(
+        "The scheduling.rzx_templates.py has been deprecated "
+        "and replaced by transformation.rzx_templates.py.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     return rzx_dict

qiskit/transpiler/passes/transformation/__init__.py

@@ -0,0 +1,16 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2020.
+#
+# 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.
+
+"""Module containing circuit transformation passes."""
+
+from .calibration_creators import CalibrationCreator, RZXCalibrationBuilder
+from .rzx_templates import rzx_templates