Remove cached_property backport (#6398)

We require recent-enough Python which has `functools.cached_property`.

Fixes #6395

Author: Josha91

cirq-core/cirq/_compat.py

@@ -61,12 +61,6 @@ def with_debug(value: bool) -> Iterator[None]:
         __cirq_debug__.reset(token)
 
 
-try:
-    from functools import cached_property  # pylint: disable=unused-import
-except ImportError:
-    from backports.cached_property import cached_property  # type: ignore[no-redef]
-
-
 # Sentinel used by wrapped_no_args below when method has not yet been cached.
 _NOT_FOUND = object()
 

cirq-core/cirq/_compat_test.py

@@ -38,7 +38,6 @@
 from cirq._compat import (
     block_overlapping_deprecation,
     cached_method,
-    cached_property,
     proper_repr,
     dataclass_repr,
     deprecated,
@@ -1011,23 +1010,6 @@ def f(x):
         f(5)
 
 
-def test_cached_property():
-    class Foo:
-        def __init__(self):
-            self.bar_calls = 0
-
-        @cached_property
-        def bar(self):
-            self.bar_calls += 1
-            return []
-
-    foo = Foo()
-    bar = foo.bar
-    bar2 = foo.bar
-    assert bar2 is bar
-    assert foo.bar_calls == 1
-
-
 class Bar:
     def __init__(self) -> None:
         self.foo_calls: Dict[int, int] = collections.Counter()

cirq-core/cirq/circuits/circuit_operation.py

@@ -19,6 +19,7 @@
 component operations in order, including any nested CircuitOperations.
 """
 import math
+from functools import cached_property
 from typing import (
     Callable,
     cast,
@@ -38,7 +39,7 @@
 import sympy
 
 from cirq import circuits, ops, protocols, value, study
-from cirq._compat import cached_property, proper_repr
+from cirq._compat import proper_repr
 
 if TYPE_CHECKING:
     import cirq

cirq-core/cirq/circuits/frozen_circuit.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """An immutable version of the Circuit data structure."""
+from functools import cached_property
 from typing import (
     AbstractSet,
     FrozenSet,
@@ -90,7 +91,7 @@ def tags(self) -> Tuple[Hashable, ...]:
         """Returns a tuple of the Circuit's tags."""
         return self._tags
 
-    @_compat.cached_property
+    @cached_property
     def untagged(self) -> 'cirq.FrozenCircuit':
         """Returns the underlying FrozenCircuit without any tags."""
         return self._from_moments(self._moments) if self.tags else self
@@ -148,7 +149,7 @@ def _is_measurement_(self) -> bool:
     def all_qubits(self) -> FrozenSet['cirq.Qid']:
         return super().all_qubits()
 
-    @_compat.cached_property
+    @cached_property
     def _all_operations(self) -> Tuple['cirq.Operation', ...]:
         return tuple(super().all_operations())
 

cirq-core/cirq/devices/superconducting_qubits_noise_properties.py

@@ -17,9 +17,10 @@
 
 import abc
 from dataclasses import dataclass, field
+from functools import cached_property
 from typing import Dict, TYPE_CHECKING, List, Set, Type
 
-from cirq import _compat, ops, devices
+from cirq import ops, devices
 from cirq.devices import noise_utils
 
 if TYPE_CHECKING:
@@ -131,7 +132,7 @@ def _get_pauli_error(self, p_error: float, op_id: noise_utils.OpIdentifier):
             p_error -= noise_utils.decoherence_pauli_error(self.t1_ns[q], self.tphi_ns[q], time_ns)
         return p_error
 
-    @_compat.cached_property
+    @cached_property
     def _depolarizing_error(self) -> Dict[noise_utils.OpIdentifier, float]:
         """Returns the portion of Pauli error from depolarization."""
         depol_errors = {}

cirq-core/cirq/ops/clifford_gate.py

@@ -20,7 +20,7 @@
 
 from cirq import protocols, value, linalg, qis
 from cirq._import import LazyLoader
-from cirq._compat import cached_property, cached_method
+from cirq._compat import cached_method
 from cirq.ops import common_gates, named_qubit, raw_types, pauli_gates, phased_x_z_gate
 from cirq.ops.pauli_gates import Pauli
 from cirq.type_workarounds import NotImplementedType
@@ -693,7 +693,7 @@ def to_phased_xz_gate(self) -> phased_x_z_gate.PhasedXZGate:
         """
         return self._to_phased_xz_gate
 
-    @cached_property
+    @functools.cached_property
     def _to_phased_xz_gate(self) -> phased_x_z_gate.PhasedXZGate:
         x_to_flip, z_to_flip = self.clifford_tableau.rs
         flip_index = int(z_to_flip) * 2 + x_to_flip
@@ -792,7 +792,7 @@ def _has_unitary_(self) -> bool:
     def _unitary_(self) -> np.ndarray:
         return self._unitary
 
-    @cached_property
+    @functools.cached_property
     def _unitary(self) -> np.ndarray:
         mat = np.eye(2)
         qubit = named_qubit.NamedQubit('arbitrary')
@@ -810,7 +810,7 @@ def decompose_gate(self) -> Sequence['cirq.Gate']:
         """
         return self._decompose_gate
 
-    @cached_property
+    @functools.cached_property
     def _decompose_gate(self) -> Sequence['cirq.Gate']:
         if self == SingleQubitCliffordGate.H:
             return [common_gates.H]
@@ -829,7 +829,7 @@ def decompose_rotation(self) -> Sequence[Tuple[Pauli, int]]:
         """
         return self._decompose_rotation
 
-    @cached_property
+    @functools.cached_property
     def _decompose_rotation(self) -> Sequence[Tuple[Pauli, int]]:
         x_rot = self.pauli_tuple(pauli_gates.X)
         y_rot = self.pauli_tuple(pauli_gates.Y)
@@ -926,7 +926,7 @@ def _circuit_diagram_info_(
     def _value_equality_values_(self):
         return self._value_equality_values
 
-    @cached_property
+    @functools.cached_property
     def _value_equality_values(self):
         return self._clifford_tableau.matrix().tobytes() + self._clifford_tableau.rs.tobytes()
 

cirq-core/cirq/ops/control_values.py

@@ -12,10 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import abc
+from functools import cached_property
 from typing import Collection, Tuple, TYPE_CHECKING, Any, Dict, Iterator, Optional, Sequence, Union
 import itertools
 
-from cirq import protocols, value, _compat
+from cirq import protocols, value
 
 if TYPE_CHECKING:
     import cirq
@@ -144,7 +145,7 @@ def __init__(self, data: Sequence[Union[int, Collection[int]]]):
             (cv,) if isinstance(cv, int) else tuple(sorted(set(cv))) for cv in data
         )
 
-    @_compat.cached_property
+    @cached_property
     def is_trivial(self) -> bool:
         return self._qubit_sums == ((1,),) * self._num_qubits_()
 
@@ -252,7 +253,7 @@ def __init__(self, data: Collection[Sequence[int]], *, name: Optional[str] = Non
         if not all(len(p) == num_qubits for p in self._conjunctions):
             raise ValueError(f'Each term of {self._conjunctions} should be of length {num_qubits}.')
 
-    @_compat.cached_property
+    @cached_property
     def is_trivial(self) -> bool:
         return self._conjunctions == ((1,) * self._num_qubits_(),)
 

cirq-core/cirq/sim/state_vector_simulator.py

@@ -14,6 +14,7 @@
 """Abstract classes for simulations which keep track of state vector."""
 
 import abc
+from functools import cached_property
 from typing import Any, Dict, Iterator, Sequence, Type, TYPE_CHECKING, Generic, TypeVar
 
 import numpy as np
@@ -121,7 +122,7 @@ def __init__(
             qubit_map=final_simulator_state.qubit_map,
         )
 
-    @_compat.cached_property
+    @cached_property
     def final_state_vector(self) -> np.ndarray:
         return self._get_merged_sim_state().target_tensor.reshape(-1)
 

cirq-ft/cirq_ft/algos/and_gate.py

@@ -12,14 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from functools import cached_property
 from typing import Sequence, Tuple
 
 import numpy as np
 from numpy.typing import NDArray
 
 import attr
 import cirq
-from cirq._compat import cached_property
 from cirq_ft import infra
 
 

cirq-ft/cirq_ft/algos/apply_gate_to_lth_target.py

@@ -12,13 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from functools import cached_property
 import itertools
 from typing import Callable, Sequence, Tuple
 
 import attr
 import cirq
 import numpy as np
-from cirq._compat import cached_property
 from cirq_ft import infra
 from cirq_ft.algos import unary_iteration_gate