Add ruff check to CI and clean up Python

.github/workflows/lint.yml

@@ -15,8 +15,8 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: '3.x'
-    - name: Install black and pylint
-      run: pip install black pylint
+    - name: Install black, pylint and ruff
+      run: pip install black pylint ruff
     - name: Check files are formatted with black
       run: |
         # Paths specified to avoid formatting submodules
@@ -25,3 +25,7 @@ jobs:
       run: |
         cd pytket
         pylint --ignore-paths=pytket/_tket pytket/
+    - name: ruff check
+      run: |
+        cd pytket
+        ruff check .

pytket/conanfile.py

@@ -1,5 +1,5 @@
 from conan import ConanFile
-from conan.tools.cmake import CMakeToolchain, CMake, cmake_layout, CMakeDeps
+from conan.tools.cmake import CMake, CMakeDeps, CMakeToolchain, cmake_layout
 
 
 class pytketRecipe(ConanFile):

pytket/docs/check_circuit_class_docs.py

@@ -6,7 +6,7 @@
 # This script is used to check that no methods or properties of
 # the Circuit class are left out in the circuit_class.rst file.
 
-with open("circuit_class.rst", "r", encoding="utf-8") as file:
+with open("circuit_class.rst", encoding="utf-8") as file:
     rst = file.read()
 
 in_methods = {p[0] for p in inspect.getmembers(Circuit)}

pytket/pytket/__init__.py

@@ -14,20 +14,20 @@
 
 """Python Interface to tket
 """
+import pytket.architecture  # noqa: I001
 from pytket.circuit import (
     Circuit,
     OpType,
 )
-from pytket.unit_id import (
-    Qubit,
-    Bit,
-)
 import pytket.mapping
-import pytket.architecture
 import pytket.placement
 import pytket.transform
-from pytket.config import PytketConfig, get_config_file_path
 from pytket._version import __version__
+from pytket.config import PytketConfig, get_config_file_path
+from pytket.unit_id import (
+    Bit,
+    Qubit,
+)
 
 # Create pytket config file if it does not exist:
 pytket_config_file = get_config_file_path()

pytket/pytket/backends/__init__.py

@@ -17,6 +17,6 @@
 __path__ = __import__("pkgutil").extend_path(__path__, __name__)
 
 from .backend import Backend
+from .backend_exceptions import CircuitNotRunError, CircuitNotValidError
 from .resulthandle import ResultHandle
 from .status import CircuitStatus, StatusEnum
-from .backend_exceptions import CircuitNotRunError, CircuitNotValidError

pytket/pytket/backends/backend.py

@@ -15,40 +15,29 @@
 """ Abstract base class for all Backend encapsulations."""
 import warnings
 from abc import ABC, abstractmethod
-from typing import (
-    Dict,
-    Iterable,
-    List,
-    Optional,
-    Sequence,
-    Union,
-    Any,
-    cast,
-    overload,
-)
+from collections.abc import Iterable, Sequence
 from importlib import import_module
 from types import ModuleType
-
-from typing_extensions import Literal
+from typing import Any, Literal, cast, overload
 
 from pytket.circuit import Bit, Circuit, OpType
 from pytket.passes import BasePass
 from pytket.pauli import QubitPauliString
 from pytket.predicates import Predicate
+from pytket.utils import QubitPauliOperator
 from pytket.utils.outcomearray import OutcomeArray
 from pytket.utils.results import KwargTypes
-from pytket.utils import QubitPauliOperator
 
 from .backend_exceptions import (
-    CircuitNotValidError,
     CircuitNotRunError,
+    CircuitNotValidError,
 )
 from .backendinfo import BackendInfo
 from .backendresult import BackendResult
 from .resulthandle import ResultHandle, _ResultIdTuple
 from .status import CircuitStatus
 
-ResultCache = Dict[str, Any]
+ResultCache = dict[str, Any]
 
 
 class ResultHandleTypeError(Exception):
@@ -73,7 +62,7 @@ class Backend(ABC):
     _persistent_handles = False
 
     def __init__(self) -> None:
-        self._cache: Dict[ResultHandle, ResultCache] = {}
+        self._cache: dict[ResultHandle, ResultCache] = {}
 
     @staticmethod
     def empty_result(circuit: Circuit, n_shots: int) -> BackendResult:
@@ -85,7 +74,7 @@ def empty_result(circuit: Circuit, n_shots: int) -> BackendResult:
 
     @property
     @abstractmethod
-    def required_predicates(self) -> List[Predicate]:
+    def required_predicates(self) -> list[Predicate]:
         """
         The minimum set of predicates that a circuit must satisfy before it can
         be successfully run on this backend.
@@ -107,7 +96,7 @@ def valid_circuit(self, circuit: Circuit) -> bool:
         return all(pred.verify(circuit) for pred in self.required_predicates)
 
     def _check_all_circuits(
-        self, circuits: Iterable[Circuit], nomeasure_warn: Optional[bool] = None
+        self, circuits: Iterable[Circuit], nomeasure_warn: bool | None = None
     ) -> bool:
         if nomeasure_warn is None:
             nomeasure_warn = not (
@@ -185,7 +174,7 @@ def get_compiled_circuit(
 
     def get_compiled_circuits(
         self, circuits: Sequence[Circuit], optimisation_level: int = 2
-    ) -> List[Circuit]:
+    ) -> list[Circuit]:
         """Compile a sequence of circuits with :py:meth:`default_compilation_pass`
         and return the list of compiled circuits (does not act in place).
 
@@ -237,15 +226,14 @@ def _check_handle_type(self, reshandle: ResultHandle) -> None:
             isinstance(idval, ty) for idval, ty in zip(reshandle, self._result_id_type)
         ):
             raise ResultHandleTypeError(
-                "{0!r} does not match expected identifier types {1}".format(
-                    reshandle, self._result_id_type
-                )
+                f"{reshandle!r} does not match expected "
+                f"identifier types {self._result_id_type}"
             )
 
     def process_circuit(
         self,
         circuit: Circuit,
-        n_shots: Optional[int] = None,
+        n_shots: int | None = None,
         valid_check: bool = True,
         **kwargs: KwargTypes,
     ) -> ResultHandle:
@@ -262,10 +250,10 @@ def process_circuit(
     def process_circuits(
         self,
         circuits: Sequence[Circuit],
-        n_shots: Optional[Union[int, Sequence[int]]] = None,
+        n_shots: int | Sequence[int] | None = None,
         valid_check: bool = True,
         **kwargs: KwargTypes,
-    ) -> List[ResultHandle]:
+    ) -> list[ResultHandle]:
         """
         Submit circuits to the backend for running. The results will be stored
         in the backend's result cache to be retrieved by the corresponding
@@ -316,7 +304,7 @@ def empty_cache(self) -> None:
         """Manually empty the result cache on the backend."""
         self._cache = {}
 
-    def pop_result(self, handle: ResultHandle) -> Optional[ResultCache]:
+    def pop_result(self, handle: ResultHandle) -> ResultCache | None:
         """Remove cache entry corresponding to handle from the cache and return.
 
         :param handle: ResultHandle object
@@ -348,7 +336,7 @@ def get_result(self, handle: ResultHandle, **kwargs: KwargTypes) -> BackendResul
 
     def get_results(
         self, handles: Iterable[ResultHandle], **kwargs: KwargTypes
-    ) -> List[BackendResult]:
+    ) -> list[BackendResult]:
         """Return results corresponding to handles.
 
         :param handles: Iterable of handles
@@ -372,7 +360,7 @@ def get_results(
     def run_circuit(
         self,
         circuit: Circuit,
-        n_shots: Optional[int] = None,
+        n_shots: int | None = None,
         valid_check: bool = True,
         **kwargs: KwargTypes,
     ) -> BackendResult:
@@ -396,10 +384,10 @@ def run_circuit(
     def run_circuits(
         self,
         circuits: Sequence[Circuit],
-        n_shots: Optional[Union[int, Sequence[int]]] = None,
+        n_shots: int | Sequence[int] | None = None,
         valid_check: bool = True,
         **kwargs: KwargTypes,
-    ) -> List[BackendResult]:
+    ) -> list[BackendResult]:
         """
         Submits circuits to the backend and returns results
 
@@ -430,7 +418,7 @@ def cancel(self, handle: ResultHandle) -> None:
         raise NotImplementedError("Backend does not support job cancellation.")
 
     @property
-    def backend_info(self) -> Optional[BackendInfo]:
+    def backend_info(self) -> BackendInfo | None:
         """Retrieve all Backend properties in a BackendInfo object, including
         device architecture, supported gate set, gate errors and other hardware-specific
         information.
@@ -441,7 +429,7 @@ def backend_info(self) -> Optional[BackendInfo]:
         raise NotImplementedError("Backend does not provide any device properties.")
 
     @classmethod
-    def available_devices(cls, **kwargs: Any) -> List[BackendInfo]:
+    def available_devices(cls, **kwargs: Any) -> list[BackendInfo]:
         """Retrieve all available devices as a list of BackendInfo objects, including
         device name, architecture, supported gate set, gate errors,
         and other hardware-specific information.
@@ -516,7 +504,7 @@ def supports_contextual_optimisation(self) -> bool:
         See :py:meth:`process_circuits`."""
         return self._supports_contextual_optimisation
 
-    def _get_extension_module(self) -> Optional[ModuleType]:
+    def _get_extension_module(self) -> ModuleType | None:
         """Return the extension module of the backend if it belongs to a
         pytket-extension package.
 
@@ -530,7 +518,7 @@ def _get_extension_module(self) -> Optional[ModuleType]:
         return import_module(".".join(mod_parts))
 
     @property
-    def __extension_name__(self) -> Optional[str]:
+    def __extension_name__(self) -> str | None:
         """Retrieve the extension name of the backend if it belongs to a
         pytket-extension package.
 
@@ -544,7 +532,7 @@ def __extension_name__(self) -> Optional[str]:
             return None
 
     @property
-    def __extension_version__(self) -> Optional[str]:
+    def __extension_version__(self) -> str | None:
         """Retrieve the extension version of the backend if it belongs to a
         pytket-extension package.
 
@@ -560,36 +548,36 @@ def __extension_version__(self) -> Optional[str]:
     @overload
     @staticmethod
     def _get_n_shots_as_list(
-        n_shots: Union[None, int, Sequence[Optional[int]]],
+        n_shots: None | int | Sequence[int | None],
         n_circuits: int,
         optional: Literal[False],
-    ) -> List[int]: ...
+    ) -> list[int]: ...
 
     @overload
     @staticmethod
     def _get_n_shots_as_list(
-        n_shots: Union[None, int, Sequence[Optional[int]]],
+        n_shots: None | int | Sequence[int | None],
         n_circuits: int,
         optional: Literal[True],
         set_zero: Literal[True],
-    ) -> List[int]: ...
+    ) -> list[int]: ...
 
     @overload
     @staticmethod
     def _get_n_shots_as_list(
-        n_shots: Union[None, int, Sequence[Optional[int]]],
+        n_shots: None | int | Sequence[int | None],
         n_circuits: int,
         optional: bool = True,
         set_zero: bool = False,
-    ) -> Union[List[Optional[int]], List[int]]: ...
+    ) -> list[int | None] | list[int]: ...
 
     @staticmethod
     def _get_n_shots_as_list(
-        n_shots: Union[None, int, Sequence[Optional[int]]],
+        n_shots: None | int | Sequence[int | None],
         n_circuits: int,
         optional: bool = True,
         set_zero: bool = False,
-    ) -> Union[List[Optional[int]], List[int]]:
+    ) -> list[int | None] | list[int]:
         """
         Convert any admissible n_shots value into List[Optional[int]] format.
 
@@ -609,9 +597,9 @@ def _get_n_shots_as_list(
         :return: a list of length `n_circuits`, the converted argument
         """
 
-        n_shots_list: List[Optional[int]] = []
+        n_shots_list: list[int | None] = []
 
-        def validate_n_shots(n: Optional[int]) -> bool:
+        def validate_n_shots(n: int | None) -> bool:
             return optional or (n is not None and n > 0)
 
         if set_zero and not optional:

pytket/pytket/backends/backend_exceptions.py

@@ -12,14 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Union, Optional
 from .resulthandle import ResultHandle
 
 
 class CircuitNotValidError(Exception):
     """Raised when a submitted circuit does not satisfy all predicates"""
 
-    def __init__(self, message: Union[str, int], failed_pred: Optional[str] = None):
+    def __init__(self, message: str | int, failed_pred: str | None = None):
         if isinstance(message, int):
             message = (
                 "Circuit with index {0} in submitted does not satisfy "
@@ -34,15 +33,13 @@ class CircuitNotRunError(Exception):
 
     def __init__(self, handle: ResultHandle):
         super().__init__(
-            "Circuit corresponding to {0!r} ".format(handle)
-            + "has not been run by this backend instance."
+            f"Circuit corresponding to {handle!r} "
+            "has not been run by this backend instance."
         )
 
 
 class InvalidResultType(Exception):
     """Raised when a BackendResult instance cannot produce the required result type."""
 
     def __init__(self, result_type: str):
-        super().__init__(
-            "BackendResult cannot produce result of type {}.".format(result_type)
-        )
+        super().__init__(f"BackendResult cannot produce result of type {result_type}.")