Remove gate argument from qiskit.transpiler.passes.Decompose

qiskit/transpiler/passes/basis/decompose.py

@@ -11,69 +11,30 @@
 # that they have been altered from the originals.
 
 """Expand a gate in a circuit using its decomposition rules."""
-import warnings
 from typing import Type, Union, List, Optional
 from fnmatch import fnmatch
 
 from qiskit.transpiler.basepasses import TransformationPass
 from qiskit.dagcircuit.dagcircuit import DAGCircuit
 from qiskit.converters.circuit_to_dag import circuit_to_dag
 from qiskit.circuit.gate import Gate
-from qiskit.utils.deprecation import deprecate_arguments
 
 
 class Decompose(TransformationPass):
     """Expand a gate in a circuit using its decomposition rules."""
 
-    @deprecate_arguments({"gate": "gates_to_decompose"})
     def __init__(
         self,
-        gate: Optional[Type[Gate]] = None,
         gates_to_decompose: Optional[Union[Type[Gate], List[Type[Gate]], List[str], str]] = None,
     ) -> None:
         """Decompose initializer.
 
         Args:
-            gate: DEPRECATED gate to decompose.
             gates_to_decompose: optional subset of gates to be decomposed,
                 identified by gate label, name or type. Defaults to all gates.
         """
         super().__init__()
-
-        if gate is not None:
-            self.gates_to_decompose = gate
-        else:
-            self.gates_to_decompose = gates_to_decompose
-
-    @property
-    def gate(self) -> Gate:
-        """Returns the gate"""
-        warnings.warn(
-            "The gate argument is deprecated as of qiskit-terra 0.19.0, and "
-            "will be removed no earlier than 3 months after that "
-            "release date. You should use the gates_to_decompose argument "
-            "instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self.gates_to_decompose
-
-    @gate.setter
-    def gate(self, value):
-        """Sets the gate
-
-        Args:
-            value (Gate): new value for gate
-        """
-        warnings.warn(
-            "The gate argument is deprecated as of qiskit-terra 0.19.0, and "
-            "will be removed no earlier than 3 months after that "
-            "release date. You should use the gates_to_decompose argument "
-            "instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        self.gates_to_decompose = value
+        self.gates_to_decompose = gates_to_decompose
 
     def run(self, dag: DAGCircuit) -> DAGCircuit:
         """Run the Decompose pass on `dag`.

releasenotes/notes/remove_gates_to_decompose-7099068d2886dce2.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    The ``gate`` argument to the transpiler pass :class:`~.Decompose` was deprecated in Terra 0.19 and is now removed.

test/python/transpiler/test_decompose.py

@@ -78,9 +78,7 @@ def test_decompose_none(self):
         circuit = QuantumCircuit(qr)
         circuit.h(qr[0])
         dag = circuit_to_dag(circuit)
-        pass_ = Decompose(HGate)
-        with self.assertWarns(DeprecationWarning):
-            pass_.gate = None
+        pass_ = Decompose()
         after_dag = pass_.run(dag)
         op_nodes = after_dag.op_nodes()
         self.assertEqual(len(op_nodes), 1)