More fixes for next version of mypy (#5628)

The cast in `fsim_gate_family` could be done with an assert, but in this case I think it is more readable to just use the cast.

Author: dabacon

cirq-core/cirq/ops/pauli_interaction_gate.py

@@ -24,7 +24,7 @@
 if TYPE_CHECKING:
     import cirq
 
-PAULI_EIGEN_MAP: Dict[pauli_gates.Pauli, np.ndarray] = {
+PAULI_EIGEN_MAP: Dict[pauli_gates.Pauli, Tuple[np.ndarray, np.ndarray]] = {
     pauli_gates.X: (np.array([[0.5, 0.5], [0.5, 0.5]]), np.array([[0.5, -0.5], [-0.5, 0.5]])),
     pauli_gates.Y: (np.array([[0.5, -0.5j], [0.5j, 0.5]]), np.array([[0.5, 0.5j], [-0.5j, 0.5]])),
     pauli_gates.Z: (np.diag([1, 0]), np.diag([0, 1])),

cirq-core/cirq/protocols/apply_channel_protocol.py

@@ -162,7 +162,9 @@ def _apply_channel_(
 
 
 def apply_channel(
-    val: Any, args: ApplyChannelArgs, default: TDefault = RaiseTypeErrorIfNotProvided
+    val: Any,
+    args: ApplyChannelArgs,
+    default: Union[np.ndarray, TDefault] = RaiseTypeErrorIfNotProvided,
 ) -> Union[np.ndarray, TDefault]:
     """High performance evolution under a channel evolution.
 

cirq-core/cirq/protocols/apply_mixture_protocol.py

@@ -155,7 +155,10 @@ def _apply_mixture_(
 
 
 def apply_mixture(
-    val: Any, args: ApplyMixtureArgs, *, default: TDefault = RaiseTypeErrorIfNotProvided
+    val: Any,
+    args: ApplyMixtureArgs,
+    *,
+    default: Union[np.ndarray, TDefault] = RaiseTypeErrorIfNotProvided,
 ) -> Union[np.ndarray, TDefault]:
     """High performance evolution under a mixture of unitaries evolution.
 
@@ -357,9 +360,7 @@ def _apply_unitary_from_matrix_strat(
     return args.target_tensor
 
 
-def _mixture_strat(
-    val: Any, args: 'ApplyMixtureArgs', is_density_matrix: bool
-) -> Optional[np.ndarray]:
+def _mixture_strat(val: Any, args: 'ApplyMixtureArgs', is_density_matrix: bool) -> np.ndarray:
     """Attempt to use unitary matrices in _mixture_ and return the result."""
     args.out_buffer[:] = 0
     np.copyto(dst=args.auxiliary_buffer1, src=args.target_tensor)

cirq-core/cirq/protocols/apply_unitary_protocol.py

@@ -277,7 +277,7 @@ def _apply_unitary_(
 def apply_unitary(
     unitary_value: Any,
     args: ApplyUnitaryArgs,
-    default: TDefault = RaiseTypeErrorIfNotProvided,
+    default: Union[np.ndarray, TDefault] = RaiseTypeErrorIfNotProvided,
     *,
     allow_decompose: bool = True,
 ) -> Union[np.ndarray, TDefault]:

cirq-core/cirq/protocols/commutes_protocol.py

@@ -78,7 +78,7 @@ def commutes(
     v2: Any,
     *,
     atol: Union[int, float] = 1e-8,
-    default: TDefault = RaiseTypeErrorIfNotProvided,
+    default: Union[bool, TDefault] = RaiseTypeErrorIfNotProvided,
 ) -> Union[bool, TDefault]:
     """Determines whether two values commute.
 

cirq-core/cirq/protocols/unitary_protocol.py

@@ -77,7 +77,7 @@ def _has_unitary_(self) -> bool:
 
 
 def unitary(
-    val: Any, default: TDefault = RaiseTypeErrorIfNotProvided
+    val: Any, default: Union[np.ndarray, TDefault] = RaiseTypeErrorIfNotProvided
 ) -> Union[np.ndarray, TDefault]:
     """Returns a unitary matrix describing the given value.
 

cirq-core/cirq/sim/sparse_simulator_test.py

@@ -331,7 +331,9 @@ def test_simulate_random_unitary(dtype: Type[np.complexfloating], split: bool):
             result = simulator.simulate(random_circuit, qubit_order=[q0, q1], initial_state=x)
             circuit_unitary.append(result.final_state_vector)
         np.testing.assert_almost_equal(
-            np.transpose(circuit_unitary), random_circuit.unitary(qubit_order=[q0, q1]), decimal=6
+            np.transpose(np.array(circuit_unitary)),
+            random_circuit.unitary(qubit_order=[q0, q1]),
+            decimal=6,
         )
 
 

cirq-google/cirq_google/ops/fsim_gate_family.py

@@ -42,7 +42,7 @@
 
 def _exp(theta: Union[complex, sympy.Basic]):
     """Utility method to return exp(theta) using numpy or sympy, depending on the type of theta."""
-    return sympy.exp(theta) if cirq.is_parameterized(theta) else np.exp(theta)
+    return sympy.exp(theta) if cirq.is_parameterized(theta) else np.exp(cast(complex, theta))
 
 
 def _gates_to_str(gates: Iterable[Any], gettr: Callable[[Any], str] = _gate_str) -> str:
@@ -360,7 +360,7 @@ def _convert_to_fsim(self, g: POSSIBLE_FSIM_GATES) -> Optional[cirq.FSimGate]:
     def _convert_to_phased_fsim(self, g: POSSIBLE_FSIM_GATES) -> Optional[cirq.PhasedFSimGate]:
         if isinstance(g, cirq.PhasedFSimGate):
             return g
-        chi = 0
+        chi = 0.0
         if isinstance(g, cirq.PhasedISwapPowGate):
             chi = g.phase_exponent * 2 * np.pi
             g = g._iswap
@@ -376,7 +376,7 @@ def _convert_to_iswap(self, g: POSSIBLE_FSIM_GATES) -> Optional[cirq.ISwapPowGat
         return (
             None
             if (fsim is None or not self._approx_eq_or_symbol(fsim.phi, 0))
-            else cirq.ISWAP ** (-2 * fsim.theta / np.pi)
+            else cirq.ISwapPowGate(exponent=-2 * fsim.theta / np.pi)
         )
 
     def _convert_to_phased_iswap(self, g: POSSIBLE_FSIM_GATES) -> Optional[cirq.PhasedISwapPowGate]:
@@ -400,7 +400,7 @@ def _convert_to_cz(self, g: POSSIBLE_FSIM_GATES) -> Optional[cirq.CZPowGate]:
         return (
             None
             if (cg is None or not self._approx_eq_or_symbol(cg.theta, 0))
-            else cirq.CZ ** (-cg.phi / np.pi)
+            else cirq.CZPowGate(exponent=-cg.phi / np.pi)
         )
 
     def _convert_to_identity(self, g: POSSIBLE_FSIM_GATES) -> Optional[cirq.IdentityGate]:

cirq-google/cirq_google/optimizers/two_qubit_gates/example.py

@@ -80,16 +80,16 @@ def main(samples: int = 1000, max_infidelity: float = 0.01):
 
     print(f'Gate compilation time : {t_comp:.3f} seconds ({t_comp / samples:.4f} s per gate)')
 
-    infidelities = np.array(infidelities)
-    failed_infidelities = np.array(failed_infidelities)
+    infidelities_arr = np.array(infidelities)
+    failed_infidelities_arr = np.array(failed_infidelities)
 
-    if np.size(failed_infidelities):
+    if np.size(failed_infidelities_arr):
         # coverage: ignore
-        print(f'Number of "failed" compilations: {np.size(failed_infidelities)}.')
-        print(f'Maximum infidelity of "failed" compilation: {np.max(failed_infidelities)}')
+        print(f'Number of "failed" compilations: {np.size(failed_infidelities_arr)}.')
+        print(f'Maximum infidelity of "failed" compilation: {np.max(failed_infidelities_arr)}')
 
     plt.figure()
-    plt.hist(infidelities, bins=25, range=[0, max_infidelity * 1.1])
+    plt.hist(infidelities_arr, bins=25, range=[0, max_infidelity * 1.1])
     ylim = plt.ylim()
     plt.plot([max_infidelity] * 2, ylim, '--', label='Maximum tabulation infidelity')
     plt.xlabel('Compiled gate infidelity vs target')