Fix mypy errors (transpiler) (#8266)

* Fix transpiler mypy errors

* Fix review comments, add a bit more annotations

* Fix annotation

* Fix sphinx

* Fix lint

* Update dynamical_decoupling.py

* Replace deprecated function call

* Update qiskit/transpiler/passes/layout/disjoint_utils.py

Co-authored-by: Luciano Bello <bel@zurich.ibm.com>

* Fix type definition

---------

Co-authored-by: Luciano Bello <bel@zurich.ibm.com>

qiskit/transpiler/instruction_durations.py

@@ -11,8 +11,10 @@
 # that they have been altered from the originals.
 
 """Durations of instructions, one of transpiler configurations."""
-from typing import Optional, List, Tuple, Union, Iterable, Set
+from __future__ import annotations
+from typing import Optional, List, Tuple, Union, Iterable
 
+import qiskit.circuit
 from qiskit.circuit import Barrier, Delay
 from qiskit.circuit import Instruction, Qubit, ParameterExpression
 from qiskit.circuit.duration import duration_in_dt
@@ -22,7 +24,7 @@
 from qiskit.utils.units import apply_prefix
 
 
-def _is_deprecated_qubits_argument(qubits: Union[int, List[int], Qubit, List[Qubit]]) -> bool:
+def _is_deprecated_qubits_argument(qubits: Union[int, list[int], Qubit, list[Qubit]]) -> bool:
     if isinstance(qubits, (int, Qubit)):
         qubits = [qubits]
     return isinstance(qubits[0], Qubit)
@@ -41,11 +43,13 @@ class InstructionDurations:
     """
 
     def __init__(
-        self, instruction_durations: Optional["InstructionDurationsType"] = None, dt: float = None
+        self, instruction_durations: "InstructionDurationsType" | None = None, dt: float = None
     ):
-        self.duration_by_name = {}
-        self.duration_by_name_qubits = {}
-        self.duration_by_name_qubits_params = {}
+        self.duration_by_name: dict[str, tuple[float, str]] = {}
+        self.duration_by_name_qubits: dict[tuple[str, tuple[int, ...]], tuple[float, str]] = {}
+        self.duration_by_name_qubits_params: dict[
+            tuple[str, tuple[int, ...], tuple[float, ...]], tuple[float, str]
+        ] = {}
         self.dt = dt
         if instruction_durations:
             self.update(instruction_durations)
@@ -99,7 +103,7 @@ def from_backend(cls, backend: Backend):
 
         return InstructionDurations(instruction_durations, dt=dt)
 
-    def update(self, inst_durations: Optional["InstructionDurationsType"], dt: float = None):
+    def update(self, inst_durations: "InstructionDurationsType" | None, dt: float = None):
         """Update self with inst_durations (inst_durations overwrite self).
 
         Args:
@@ -177,10 +181,10 @@ def update(self, inst_durations: Optional["InstructionDurationsType"], dt: float
     )
     def get(
         self,
-        inst: Union[str, Instruction],
-        qubits: Union[int, List[int], Qubit, List[Qubit]],
+        inst: str | qiskit.circuit.Instruction,
+        qubits: int | list[int] | Qubit | list[Qubit] | list[int | Qubit],
         unit: str = "dt",
-        parameters: Optional[List[float]] = None,
+        parameters: list[float] | None = None,
     ) -> float:
         """Get the duration of the instruction with the name, qubits, and parameters.
 
@@ -224,9 +228,9 @@ def get(
     def _get(
         self,
         name: str,
-        qubits: List[int],
+        qubits: list[int],
         to_unit: str,
-        parameters: Optional[Iterable[float]] = None,
+        parameters: Iterable[float] | None = None,
     ) -> float:
         """Get the duration of the instruction with the name, qubits, and parameters."""
         if name == "barrier":
@@ -270,7 +274,7 @@ def _convert_unit(self, duration: float, from_unit: str, to_unit: str) -> float:
         else:
             raise TranspilerError(f"Conversion from '{from_unit}' to '{to_unit}' is not supported")
 
-    def units_used(self) -> Set[str]:
+    def units_used(self) -> set[str]:
         """Get the set of all units used in this instruction durations.
 
         Returns:

qiskit/transpiler/layout.py

@@ -17,9 +17,8 @@
 Virtual (qu)bits are tuples, e.g. `(QuantumRegister(3, 'qr'), 2)` or simply `qr[2]`.
 Physical (qu)bits are integers.
 """
-
+from __future__ import annotations
 from dataclasses import dataclass
-from typing import Dict, Optional
 
 from qiskit.circuit.quantumregister import Qubit, QuantumRegister
 from qiskit.transpiler.exceptions import LayoutError
@@ -262,7 +261,7 @@ def combine_into_edge_map(self, another_layout):
 
         return edge_map
 
-    def reorder_bits(self, bits):
+    def reorder_bits(self, bits) -> list[int]:
         """Given an ordered list of bits, reorder them according to this layout.
 
         The list of bits must exactly match the virtual bits in this layout.
@@ -401,5 +400,5 @@ class TranspileLayout:
     """
 
     initial_layout: Layout
-    input_qubit_mapping: Dict[Qubit, int]
-    final_layout: Optional[Layout] = None
+    input_qubit_mapping: dict[Qubit, int]
+    final_layout: Layout | None = None

qiskit/transpiler/passes/calibration/rzx_builder.py

@@ -11,11 +11,12 @@
 # that they have been altered from the originals.
 
 """RZX calibration builders."""
+from __future__ import annotations
 
 import enum
 import warnings
+from collections.abc import Sequence
 from math import pi, erf
-from typing import List, Tuple, Union
 
 import numpy as np
 from qiskit.circuit import Instruction as CircuitInst
@@ -68,7 +69,7 @@ class RZXCalibrationBuilder(CalibrationBuilder):
     def __init__(
         self,
         instruction_schedule_map: InstructionScheduleMap = None,
-        qubit_channel_mapping: List[List[str]] = None,
+        qubit_channel_mapping: list[list[str]] = None,
         verbose: bool = True,
         target: Target = None,
     ):
@@ -97,7 +98,7 @@ def __init__(
         if self._inst_map is None:
             raise QiskitError("Calibrations can only be added to Pulse-enabled backends")
 
-    def supported(self, node_op: CircuitInst, qubits: List) -> bool:
+    def supported(self, node_op: CircuitInst, qubits: list) -> bool:
         """Determine if a given node supports the calibration.
 
         Args:
@@ -166,7 +167,7 @@ def rescale_cr_inst(instruction: Play, theta: float, sample_mult: int = 16) -> i
 
         return round_duration
 
-    def get_calibration(self, node_op: CircuitInst, qubits: List) -> Union[Schedule, ScheduleBlock]:
+    def get_calibration(self, node_op: CircuitInst, qubits: list) -> Schedule | ScheduleBlock:
         """Builds the calibration schedule for the RZXGate(theta) with echos.
 
         Args:
@@ -260,7 +261,7 @@ class RZXCalibrationBuilderNoEcho(RZXCalibrationBuilder):
     of the CX gate.
     """
 
-    def get_calibration(self, node_op: CircuitInst, qubits: List) -> Union[Schedule, ScheduleBlock]:
+    def get_calibration(self, node_op: CircuitInst, qubits: list) -> Schedule | ScheduleBlock:
         """Builds the calibration schedule for the RZXGate(theta) without echos.
 
         Args:
@@ -336,8 +337,8 @@ def _filter_comp_tone(time_inst_tup):
 
 
 def _check_calibration_type(
-    inst_sched_map: InstructionScheduleMap, qubits: List[int]
-) -> Tuple[CRCalType, List[Play], List[Play]]:
+    inst_sched_map: InstructionScheduleMap, qubits: Sequence[int]
+) -> tuple[CRCalType, list[Play], list[Play]]:
     """A helper function to check type of CR calibration.
 
     Args:

qiskit/transpiler/passes/layout/disjoint_utils.py

@@ -11,12 +11,13 @@
 # that they have been altered from the originals.
 
 """This module contains common utils for disjoint coupling maps."""
-
+from __future__ import annotations
 from collections import defaultdict
 from typing import List, Callable, TypeVar, Dict, Union
 import uuid
 
 import rustworkx as rx
+from qiskit.dagcircuit import DAGOpNode
 
 from qiskit.circuit import Qubit, Barrier, Clbit
 from qiskit.dagcircuit.dagcircuit import DAGCircuit
@@ -65,7 +66,7 @@ def run_pass_over_connected_components(
             for qreg in dag.qregs:
                 out_dag.add_qreg(qreg)
             for creg in dag.cregs:
-                out_dag.add_cregs(creg)
+                out_dag.add_creg(creg)
             out_dag.compose(dag, qubits=dag.qubits, clbits=dag.clbits)
         out_component_pairs.append((out_dag, cmap_components[cmap_index]))
     res = [run_func(out_dag, cmap) for out_dag, cmap in out_component_pairs]
@@ -119,7 +120,7 @@ def split_barriers(dag: DAGCircuit):
 def combine_barriers(dag: DAGCircuit, retain_uuid: bool = True):
     """Mutate input dag to combine barriers with UUID labels into a single barrier."""
     qubit_indices = {bit: index for index, bit in enumerate(dag.qubits)}
-    uuid_map = {}
+    uuid_map: dict[uuid.UUID, DAGOpNode] = {}
     for node in dag.op_nodes(Barrier):
         if isinstance(node.op.label, uuid.UUID):
             barrier_uuid = node.op.label
@@ -139,9 +140,18 @@ def combine_barriers(dag: DAGCircuit, retain_uuid: bool = True):
 
 def require_layout_isolated_to_component(
     dag: DAGCircuit, components_source: Union[Target, CouplingMap]
-) -> bool:
-    """Check that the layout of the dag does not require connectivity across connected components
-    in the CouplingMap"""
+):
+    """
+    Check that the layout of the dag does not require connectivity across connected components
+    in the CouplingMap
+
+    Args:
+        dag: DAGCircuit to check.
+        components_source: Target to check against.
+
+    Raises:
+        TranspilerError: Chosen layout is not valid for the target disjoint connectivity.
+    """
     if isinstance(components_source, Target):
         coupling_map = components_source.build_coupling_map(filter_idle_qubits=True)
     else:

qiskit/transpiler/passes/routing/algorithms/token_swapper.py

@@ -26,9 +26,10 @@
 
 """Permutation algorithms for general graphs."""
 
+from __future__ import annotations
 import copy
 import logging
-from typing import Iterator, Mapping, MutableMapping, MutableSet, List, Iterable, Union
+from collections.abc import Mapping, MutableSet, MutableMapping, Iterator, Iterable
 
 import numpy as np
 import rustworkx as rx
@@ -46,9 +47,7 @@ class ApproximateTokenSwapper:
     Internally caches the graph and associated datastructures for re-use.
     """
 
-    def __init__(
-        self, graph: rx.PyGraph, seed: Union[int, np.random.Generator, None] = None
-    ) -> None:
+    def __init__(self, graph: rx.PyGraph, seed: int | np.random.Generator | None = None) -> None:
         """Construct an ApproximateTokenSwapping object.
 
         Args:
@@ -80,7 +79,7 @@ def permutation_circuit(self, permutation: Permutation, trials: int = 4) -> Perm
         parallel_swaps = [[swap] for swap in sequential_swaps]
         return permutation_circuit(parallel_swaps)
 
-    def map(self, mapping: Mapping[int, int], trials: int = 4) -> List[Swap[int]]:
+    def map(self, mapping: Mapping[int, int], trials: int = 4) -> list[Swap[int]]:
         """Perform an approximately optimal Token Swapping algorithm to implement the permutation.
 
         Supports partial mappings (i.e. not-permutations) for graphs with missing tokens.
@@ -113,7 +112,7 @@ def map(self, mapping: Mapping[int, int], trials: int = 4) -> List[Swap[int]]:
         )
 
         # Once we find a zero solution we stop.
-        def take_until_zero(results: Iterable[List[int]]) -> Iterator[List[int]]:
+        def take_until_zero(results: Iterable[list[Swap[int]]]) -> Iterable[list[Swap[int]]]:
             """Take results until one is emitted of length zero (and also emit that)."""
             for result in results:
                 yield result

qiskit/transpiler/passes/routing/algorithms/util.py

@@ -26,7 +26,10 @@
 
 """Utility functions shared between permutation functionality."""
 
-from typing import List, TypeVar, Iterable, MutableMapping
+from __future__ import annotations
+
+from collections.abc import Iterable
+from typing import TypeVar, MutableMapping
 
 from qiskit.circuit import QuantumRegister
 from qiskit.dagcircuit import DAGCircuit
@@ -53,8 +56,8 @@ def swap_permutation(
     for swap_step in swaps:
         for sw1, sw2 in swap_step:
             # Take into account non-existent keys.
-            val1 = None  # type: Optional[_V]
-            val2 = None  # type: Optional[_V]
+            val1: _V | None = None
+            val2: _V | None = None
             if allow_missing_keys:
                 val1 = mapping.pop(sw1, None)
                 val2 = mapping.pop(sw2, None)
@@ -68,7 +71,7 @@ def swap_permutation(
                 mapping[sw1] = val2
 
 
-def permutation_circuit(swaps: Iterable[List[Swap[_V]]]) -> PermutationCircuit:
+def permutation_circuit(swaps: Iterable[list[Swap[_V]]]) -> PermutationCircuit:
     """Produce a circuit description of a list of swaps.
         With a given permutation and permuter you can compute the swaps using the permuter function
         then feed it into this circuit function to obtain a circuit description.

qiskit/transpiler/passes/routing/commuting_2q_gate_routing/commuting_2q_block.py

@@ -11,11 +11,12 @@
 # that they have been altered from the originals.
 
 """A gate made of commuting two-qubit gates."""
+from __future__ import annotations
 
-from typing import Iterable
+from collections.abc import Iterable
 
 from qiskit.exceptions import QiskitError
-from qiskit.circuit import Gate
+from qiskit.circuit import Gate, Qubit, Clbit
 from qiskit.dagcircuit import DAGOpNode
 
 
@@ -34,7 +35,8 @@ def __init__(self, node_block: Iterable[DAGOpNode]) -> None:
         Raises:
             QiskitError: If the nodes in the node block do not apply to two-qubits.
         """
-        qubits, cbits = set(), set()
+        qubits: set[Qubit] = set()
+        cbits: set[Clbit] = set()
         for node in node_block:
             if len(node.qargs) != 2:
                 raise QiskitError(f"Node {node.name} does not apply to two-qubits.")