Cleanup python submodules in rust code (#14063)

This commit cleans up the submodule usage in our rust extension. We
shouldn't be using the pymodule attribute for submodules. This also
cleans up the submodule in the basis translator which was unnecessarily
two layers deep and also duplicated in the init file.

Author: mtreinish

crates/accelerate/src/basis/basis_translator/mod.rs

@@ -800,7 +800,6 @@ fn replace_node(
     Ok(())
 }
 
-#[pymodule]
 pub fn basis_translator(m: &Bound<PyModule>) -> PyResult<()> {
     m.add_wrapped(wrap_pyfunction!(run))?;
     Ok(())

crates/accelerate/src/basis/mod.rs

@@ -10,12 +10,4 @@
 // copyright notice, and modified files need to carry a notice indicating
 // that they have been altered from the originals.
 
-use pyo3::{prelude::*, wrap_pymodule};
-
 pub mod basis_translator;
-
-#[pymodule]
-pub fn basis(m: &Bound<PyModule>) -> PyResult<()> {
-    m.add_wrapped(wrap_pymodule!(basis_translator::basis_translator))?;
-    Ok(())
-}

crates/accelerate/src/equivalence.rs

@@ -817,7 +817,6 @@ where
     Ok(graph.unbind())
 }
 
-#[pymodule]
 pub fn equivalence(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<EquivalenceLibrary>()?;
     m.add_class::<NodeData>()?;

crates/accelerate/src/gate_direction.rs

@@ -555,7 +555,6 @@ fn rzx_replacement_dag(py: Python, param: &[Param]) -> PyResult<DAGCircuit> {
     Ok(new_dag.clone())
 }
 
-#[pymodule]
 pub fn gate_direction(m: &Bound<PyModule>) -> PyResult<()> {
     m.add_wrapped(wrap_pyfunction!(py_check_direction_coupling_map))?;
     m.add_wrapped(wrap_pyfunction!(py_check_direction_target))?;

crates/accelerate/src/unitary_synthesis.rs

@@ -1346,7 +1346,6 @@ fn run_2q_unitary_synthesis(
     Ok(())
 }
 
-#[pymodule]
 pub fn unitary_synthesis(m: &Bound<PyModule>) -> PyResult<()> {
     m.add_wrapped(wrap_pyfunction!(py_run_main_loop))?;
     Ok(())

crates/pyext/src/lib.rs

@@ -30,7 +30,7 @@ where
 #[pymodule]
 fn _accelerate(m: &Bound<PyModule>) -> PyResult<()> {
     add_submodule(m, ::qiskit_accelerate::barrier_before_final_measurement::barrier_before_final_measurements_mod, "barrier_before_final_measurement")?;
-    add_submodule(m, ::qiskit_accelerate::basis::basis, "basis")?;
+    add_submodule(m, ::qiskit_accelerate::basis::basis_translator::basis_translator, "basis_translator")?;
     add_submodule(m, ::qiskit_accelerate::check_map::check_map_mod, "check_map")?;
     add_submodule(m, ::qiskit_accelerate::circuit_duration::compute_duration, "circuit_duration")?;
     add_submodule(m, ::qiskit_accelerate::circuit_library::circuit_library, "circuit_library")?;

qiskit/__init__.py

@@ -53,11 +53,8 @@
 # and not have to rely on attribute access.  No action needed for top-level extension packages.
 sys.modules["qiskit._accelerate.circuit"] = _accelerate.circuit
 sys.modules["qiskit._accelerate.circuit_library"] = _accelerate.circuit_library
-sys.modules["qiskit._accelerate.basis"] = _accelerate.basis
-sys.modules["qiskit._accelerate.basis.basis_translator"] = _accelerate.basis.basis_translator
+sys.modules["qiskit._accelerate.basis_translator"] = _accelerate.basis_translator
 sys.modules["qiskit._accelerate.converters"] = _accelerate.converters
-sys.modules["qiskit._accelerate.basis"] = _accelerate.basis
-sys.modules["qiskit._accelerate.basis.basis_translator"] = _accelerate.basis.basis_translator
 sys.modules["qiskit._accelerate.dense_layout"] = _accelerate.dense_layout
 sys.modules["qiskit._accelerate.equivalence"] = _accelerate.equivalence
 sys.modules["qiskit._accelerate.error_map"] = _accelerate.error_map

qiskit/transpiler/passes/basis/basis_translator.py

@@ -18,7 +18,7 @@
 from collections import defaultdict
 
 from qiskit.transpiler.basepasses import TransformationPass
-from qiskit._accelerate.basis.basis_translator import base_run
+from qiskit._accelerate.basis_translator import base_run
 
 logger = logging.getLogger(__name__)