ruff fix II

pytket/extensions/cutensornet/backends/cutensornet_backend.py

@@ -17,7 +17,7 @@
 import warnings
 from abc import abstractmethod
 from collections.abc import Sequence
-from typing import List, Optional, Union
+from typing import Optional, Union
 from uuid import uuid4
 
 from pytket.backends import CircuitNotRunError, CircuitStatus, ResultHandle, StatusEnum
@@ -69,7 +69,7 @@ def _result_id_type(self) -> _ResultIdTuple:
         return (str,)
 
     @property
-    def required_predicates(self) -> List[Predicate]:
+    def required_predicates(self) -> list[Predicate]:
         """Returns the minimum set of predicates that a circuit must satisfy.
 
         Predicates need to be satisfied before the circuit can be successfully run on
@@ -145,7 +145,7 @@ def process_circuits(
         n_shots: Optional[Union[int, Sequence[int]]] = None,
         valid_check: bool = True,
         **kwargs: KwargTypes,
-    ) -> List[ResultHandle]:
+    ) -> list[ResultHandle]:
         """Submits circuits to the backend for running.
 
         The results will be stored in the backend's result cache to be retrieved by the
@@ -197,7 +197,7 @@ def process_circuits(
         n_shots: Optional[Union[int, Sequence[int]]] = None,
         valid_check: bool = True,
         **kwargs: KwargTypes,
-    ) -> List[ResultHandle]:
+    ) -> list[ResultHandle]:
         """Submits circuits to the backend for running.
 
         The results will be stored in the backend's result cache to be retrieved by the
@@ -274,7 +274,7 @@ def process_circuits(
         n_shots: Optional[Union[int, Sequence[int]]] = None,
         valid_check: bool = True,
         **kwargs: KwargTypes,
-    ) -> List[ResultHandle]:
+    ) -> list[ResultHandle]:
         """Submits circuits to the backend for running.
 
         The results will be stored in the backend's result cache to be retrieved by the

pytket/extensions/cutensornet/general.py

@@ -16,7 +16,7 @@
 import logging
 import warnings
 from logging import Logger
-from typing import Any, Optional
+from typing import Any
 
 try:
     import cupy as cp  # type: ignore
@@ -42,7 +42,7 @@ class CuTensorNetHandle:
             If not provided, defaults to ``cp.cuda.Device()``.
     """
 
-    def __init__(self, device_id: Optional[int] = None):
+    def __init__(self, device_id: int | None = None):
         self._is_destroyed = False
 
         # Make sure CuPy uses the specified device

pytket/extensions/cutensornet/general_state/tensor_network_convert.py

@@ -24,7 +24,7 @@
 import logging
 from collections import defaultdict
 from logging import Logger
-from typing import Any, DefaultDict, List, Optional, Tuple, Union
+from typing import Any, Optional, Union
 
 import networkx as nx  # type: ignore
 import numpy as np
@@ -88,7 +88,7 @@ def cuquantum_interleaved(self) -> list:
         """Returns an interleaved format of the circuit tensor network."""
         return self._cuquantum_interleaved
 
-    def _get_gate_tensors(self, adj: bool = False) -> DefaultDict[Any, List[Any]]:
+    def _get_gate_tensors(self, adj: bool = False) -> defaultdict[Any, list[Any]]:
         """Computes and stores tensors for each gate type from the circuit.
 
         The unitaries are reshaped into tensors of bond dimension two prior to being
@@ -174,7 +174,7 @@ def _get_gate_tensors(self, adj: bool = False) -> DefaultDict[Any, List[Any]]:
         self._logger.debug(f"Gate tensors: \n{gate_tensors}\n")
         return gate_tensors
 
-    def _assign_node_tensors(self, adj: bool = False) -> List[Any]:
+    def _assign_node_tensors(self, adj: bool = False) -> list[Any]:
         """Creates a list of tensors representing circuit gates (tensor network nodes).
 
         Args:
@@ -236,7 +236,7 @@ def _assign_node_tensors(self, adj: bool = False) -> List[Any]:
 
     def _get_tn_indices(
         self, net: nx.MultiDiGraph, adj: bool = False
-    ) -> Tuple[List[Any], dict[Qubit, int]]:
+    ) -> tuple[list[Any], dict[Qubit, int]]:
         """Computes indices of the edges of the tensor network nodes (tensors).
 
         Indices are computed such that they range from high (for circuit leftmost gates)
@@ -283,7 +283,7 @@ def _get_tn_indices(
         ]
         eids_sorted = sorted(eids, key=abs)
         qnames_graph_ordered = [qname for qname in self._graph.output_names.values()]
-        oids_graph_ordered = [oid for oid in self._graph.output_names.keys()]
+        oids_graph_ordered = [oid for oid in self._graph.output_names]
         eids_qubit_ordered = [
             eids_sorted[qnames_graph_ordered.index(q)] for q in self._qubit_names_ilo
         ]  # Order eid's in the same way as qnames_graph_ordered as compared to ILO
@@ -363,7 +363,7 @@ def _get_tn_indices(
 
     @staticmethod
     def _order_edges_for_multiqubit_gate(
-        edge_indices: DefaultDict[Any, List[Tuple[Any, int]]],
+        edge_indices: defaultdict[Any, list[tuple[Any, int]]],
         edges: OutMultiEdgeView,
         edges_data: OutMultiEdgeDataView,
         offset: int,
@@ -577,7 +577,7 @@ def __init__(
         self._logger = set_logger("PauliOperatorTensorNetwork", loglevel)
         self._pauli_tensors = [self.PAULI[pauli.name] for pauli in paulis.map.values()]
         self._logger.debug(f"Pauli tensors: {self._pauli_tensors}")
-        qubits = [q for q in paulis.map.keys()]
+        qubits = [q for q in paulis.map]
         # qubit_names = [
         #    "".join([q.reg_name, "".join([f"[{str(i)}]" for i in q.index])])
         #    for q in paulis.map.keys()
@@ -655,7 +655,7 @@ def _make_interleaved(self) -> list:
         return tn_concatenated
 
 
-def tk_to_tensor_network(tkc: Circuit) -> List[Union[NDArray, List]]:
+def tk_to_tensor_network(tkc: Circuit) -> list[Union[NDArray, list]]:
     """Converts pytket circuit into a tensor network.
 
     Args:

pytket/extensions/cutensornet/general_state/tensor_network_state.py

@@ -16,21 +16,24 @@
 
 import logging
 import warnings
-from typing import Dict, Optional, Tuple, Union
+from typing import TYPE_CHECKING
 
 try:
     import cupy as cp  # type: ignore
 except ImportError:
     warnings.warn("local settings failed to import cupy", ImportWarning)
 import numpy as np
-from numpy.typing import NDArray
 from sympy import Expr  # type: ignore
 
 from pytket.backends.backendresult import BackendResult
 from pytket.circuit import Bit, Circuit, OpType, Qubit
 from pytket.extensions.cutensornet.general import CuTensorNetHandle, set_logger
 from pytket.utils import OutcomeArray
-from pytket.utils.operators import QubitPauliOperator
+
+if TYPE_CHECKING:
+    from numpy.typing import NDArray
+
+    from pytket.utils.operators import QubitPauliOperator
 
 try:
     import cuquantum as cq  # type: ignore
@@ -115,10 +118,10 @@ def __init__(
 
     def get_statevector(
         self,
-        attributes: Optional[dict] = None,
+        attributes: dict | None = None,
         scratch_fraction: float = 0.75,
         on_host: bool = True,
-    ) -> Union[cp.ndarray, np.ndarray]:
+    ) -> cp.ndarray | np.ndarray:
         """Contracts the circuit and returns the final statevector.
 
         Args:
@@ -230,7 +233,7 @@ def get_statevector(
     def expectation_value(
         self,
         operator: QubitPauliOperator,
-        attributes: Optional[dict] = None,
+        attributes: dict | None = None,
         scratch_fraction: float = 0.75,
     ) -> complex:
         """Calculates the expectation value of the given operator.
@@ -275,7 +278,7 @@ def expectation_value(
             self._logger.debug(f"   {numeric_coeff}, {pauli_string}")
 
             # Raise an error if the operator acts on qubits that are not in the circuit
-            if any(q not in self._circuit.qubits for q in pauli_string.map.keys()):
+            if any(q not in self._circuit.qubits for q in pauli_string.map):
                 raise ValueError(
                     f"The operator is acting on qubits {pauli_string.map.keys()}, "
                     "but some of these are not present in the circuit, whose set of "
@@ -289,9 +292,7 @@ def expectation_value(
 
             num_pauli = len(qubit_pauli_map)
             num_modes = (1,) * num_pauli
-            state_modes = tuple(
-                (self._qubit_idx_map[qb],) for qb in qubit_pauli_map
-            )
+            state_modes = tuple((self._qubit_idx_map[qb],) for qb in qubit_pauli_map)
             gate_data = tuple(tensor.data.ptr for tensor in qubit_pauli_map.values())
 
             cutn.network_operator_append_product(
@@ -408,7 +409,7 @@ def expectation_value(
     def sample(
         self,
         n_shots: int,
-        attributes: Optional[dict] = None,
+        attributes: dict | None = None,
         scratch_fraction: float = 0.75,
     ) -> BackendResult:
         """Obtains samples from the measurements at the end of the circuit.
@@ -568,7 +569,7 @@ def _formatted_tensor(matrix: NDArray, n_qubits: int) -> cp.ndarray:
     return cupy_matrix.reshape([2] * (2 * n_qubits), order="F")
 
 
-def _remove_meas_and_implicit_swaps(circ: Circuit) -> Tuple[Circuit, Dict[Qubit, Bit]]:
+def _remove_meas_and_implicit_swaps(circ: Circuit) -> tuple[Circuit, dict[Qubit, Bit]]:
     """Convert a pytket Circuit to an equivalent circuit with no measurements or
     implicit swaps. The measurements are returned as a map between qubits and bits.
 

pytket/extensions/cutensornet/structured_state/general.py

@@ -16,7 +16,7 @@
 import logging
 import warnings
 from abc import ABC, abstractmethod
-from typing import Any, Optional, Type
+from typing import TYPE_CHECKING, Any
 
 import numpy as np  # type: ignore
 
@@ -28,17 +28,19 @@
     OpType,
     Qubit,
 )
-from pytket.pauli import QubitPauliString
 
 try:
     import cupy as cp  # type: ignore
 except ImportError:
     warnings.warn("local settings failed to import cupy", ImportWarning)
 
-from pytket.extensions.cutensornet import CuTensorNetHandle
 
 from .classical import apply_classical_command, from_little_endian
 
+if TYPE_CHECKING:
+    from pytket.extensions.cutensornet import CuTensorNetHandle
+    from pytket.pauli import QubitPauliString
+
 # An alias for the CuPy type used for tensors
 try:
     Tensor = cp.ndarray
@@ -51,10 +53,10 @@ class Config:
 
     def __init__(
         self,
-        chi: Optional[int] = None,
-        truncation_fidelity: Optional[float] = None,
-        seed: Optional[int] = None,
-        float_precision: Type[Any] = np.float64,
+        chi: int | None = None,
+        truncation_fidelity: float | None = None,
+        seed: int | None = None,
+        float_precision: type[Any] = np.float64,
         value_of_zero: float = 1e-16,
         leaf_size: int = 8,
         k: int = 4,

pytket/extensions/cutensornet/structured_state/mps.py

@@ -16,7 +16,6 @@
 import warnings
 from enum import Enum
 from random import Random  # type: ignore
-from typing import Optional, Union
 
 import numpy as np  # type: ignore
 
@@ -69,7 +68,7 @@ def __init__(
         libhandle: CuTensorNetHandle,
         qubits: list[Qubit],
         config: Config,
-        bits: Optional[list[Bit]] = None,
+        bits: list[Bit] | None = None,
     ):
         """Initialise an MPS on the computational state ``|0>``
 
@@ -269,7 +268,7 @@ def add_qubit(self, new_qubit: Qubit, position: int, state: int = 0) -> MPS:
 
         options = {"handle": self._lib.handle, "device_id": self._lib.device_id}
 
-        if new_qubit in self.qubit_position.keys():
+        if new_qubit in self.qubit_position:
             raise ValueError(
                 f"Qubit {new_qubit} cannot be added, it already is in the MPS."
             )
@@ -501,7 +500,7 @@ def vdot(self, other: MPS) -> complex:  # type: ignore
 
     def _get_interleaved_representation(
         self, conj: bool = False
-    ) -> list[Union[cp.ndarray, str]]:
+    ) -> list[cp.ndarray | str]:
         """Returns the interleaved representation of the MPS used by cuQuantum.
 
         Args:
@@ -760,7 +759,7 @@ def expectation_value(self, pauli_string: QubitPauliString) -> float:
         """
         self._flush()
 
-        for q in pauli_string.map.keys():
+        for q in pauli_string.map:
             if q not in self.qubit_position:
                 raise ValueError(f"Qubit {q} is not a qubit in the MPS.")
 

pytket/extensions/cutensornet/structured_state/mps_gate.py

@@ -27,10 +27,14 @@
 except ImportError:
     warnings.warn("local settings failed to import cutensornet", ImportWarning)
 
-from pytket.circuit import Qubit
+
+from typing import TYPE_CHECKING
 
 from .mps import MPS, DirMPS
 
+if TYPE_CHECKING:
+    from pytket.circuit import Qubit
+
 
 class MPSxGate(MPS):
     """Implements a gate-by-gate contraction algorithm to calculate the output state

pytket/extensions/cutensornet/structured_state/mps_mpo.py

@@ -14,7 +14,7 @@
 from __future__ import annotations  # type: ignore
 
 import warnings
-from typing import Optional, Union
+from typing import TYPE_CHECKING
 
 import numpy as np  # type: ignore
 
@@ -28,16 +28,19 @@
 except ImportError:
     warnings.warn("local settings failed to import cutensornet", ImportWarning)
 
-from pytket.circuit import Bit, Qubit
-from pytket.extensions.cutensornet import CuTensorNetHandle
 
-from .general import Config, Tensor
 from .mps import (
     MPS,
     DirMPS,
 )
 from .mps_gate import MPSxGate
 
+if TYPE_CHECKING:
+    from pytket.circuit import Bit, Qubit
+    from pytket.extensions.cutensornet import CuTensorNetHandle
+
+    from .general import Config, Tensor
+
 
 class MPSxMPO(MPS):
     """Implements a batched--gate contraction algorithm (DMRG-like) to calculate
@@ -50,7 +53,7 @@ def __init__(
         libhandle: CuTensorNetHandle,
         qubits: list[Qubit],
         config: Config,
-        bits: Optional[list[Bit]] = None,
+        bits: list[Bit] | None = None,
     ):
         """Initialise an MPS on the computational state ``|0>``.
 
@@ -430,7 +433,7 @@ def update_sweep_cache(pos: int, direction: DirMPS) -> None:
                 # The MPO tensor at this position
                 interleaved_rep.append(mpo_tensor)
 
-                mpo_bonds: list[Union[int, str]] = list(self._bond_ids[pos][i])
+                mpo_bonds: list[int | str] = list(self._bond_ids[pos][i])
                 if i == 0:
                     # The input bond of the first MPO tensor must connect to the
                     # physical bond of the correspondong ``self.tensors`` tensor
@@ -479,7 +482,7 @@ def update_sweep_cache(pos: int, direction: DirMPS) -> None:
             self._logger.debug("Completed update of the sweep cache.")
 
         def update_variational_tensor(
-            pos: int, left_tensor: Optional[Tensor], right_tensor: Optional[Tensor]
+            pos: int, left_tensor: Tensor | None, right_tensor: Tensor | None
         ) -> float:
             """Update the tensor at ``pos`` of the variational MPS using ``left_tensor``
             (and ``right_tensor``) which is meant to contain the contraction of all
@@ -501,7 +504,7 @@ def update_variational_tensor(
                 # The MPO tensor at this position
                 interleaved_rep.append(mpo_tensor)
 
-                mpo_bonds: list[Union[int, str]] = list(self._bond_ids[pos][i])
+                mpo_bonds: list[int | str] = list(self._bond_ids[pos][i])
                 if i == 0:
                     # The input bond of the first MPO tensor must connect to the
                     # physical bond of the correspondong ``self.tensors`` tensor