Update circuit_transpiler.py

src/qililab/digital/circuit_transpiler.py

@@ -140,14 +140,10 @@ def transpile_circuit(
 
         # Routing stage;
         if routing:
-            circuit, final_layout = self.route_circuit(circuit, placer, router, iterations=routing_iterations)
-            logger.info(f"The physical qubits used for the execution will be: {final_layout}")
+            gate_list, final_layout, nqubits = self.route_circuit(circuit, placer, router, routing_iterations)
         else:
-            final_layout = {f"q{i}": i for i in range(circuit.nqubits)}
-
-        # Transpilation is done without constructing the Circuit class, from here onwards:
-        gate_list = circuit.queue
-        nqubits = circuit.nqubits
+            gate_list, nqubits = circuit.queue, circuit.nqubits
+            final_layout = {f"q{i}": i for i in range(nqubits)}
 
         # Optimze qibo gates, cancelling redundant gates:
         if optimize:
@@ -173,9 +169,9 @@ def route_circuit(
         circuit: Circuit,
         placer: Placer | type[Placer] | tuple[type[Placer], dict] | None = None,
         router: Router | type[Router] | tuple[type[Router], dict] | None = None,
-        coupling_map: list[tuple[int, int]] | None = None,
         iterations: int = 10,
-    ) -> tuple[Circuit, dict[str, int]]:
+        coupling_map: list[tuple[int, int]] | None = None,
+    ) -> tuple[list[gates.Gate], dict[str, int], int]:
         """Routes the virtual/logical qubits of a circuit to the physical qubits of a chip. Returns and logs the final qubit layout.
 
         This process uses the provided `placer`, `router`, and `routing_iterations` parameters if they are passed; otherwise, default values are applied.
@@ -219,17 +215,16 @@ def route_circuit(
 
         Args:
             circuit (Circuit): circuit to route.
-            coupling_map (list[tuple[int, int]], optional): coupling map of the chip to route. This topology will be the one that rules,
-                which will overwrite any other in an instance of router or placer. Defaults to the platform topology.
             placer (Placer | type[Placer] | tuple[type[Placer], dict], optional): `Placer` instance, or subclass `type[Placer]` to
                 use, with optionally, its kwargs dict (other than connectivity), both in a tuple. Defaults to `ReverseTraversal`.
             router (Router | type[Router] | tuple[type[Router], dict], optional): `Router` instance, or subclass `type[Router]` to
                 use, with optionally, its kwargs dict (other than connectivity), both in a tuple. Defaults to `Sabre`.
             iterations (int, optional): Number of times to repeat the routing pipeline, to keep the best stochastic result. Defaults to 10.
-
+            coupling_map (list[tuple[int, int]], optional): coupling map of the chip to route. This topology will be the one that rules,
+                which will overwrite any other in an instance of router or placer. Defaults to the platform topology.
 
         Returns:
-            tuple[Circuit, dict[str, int]]: routed circuit, and final layout of the circuit {"qI": J}.
+            tuple[list[Gate], dict[str, int], int]: List of gates of the routed circuit, final layout of the circuit {"qI": J}, and number of qubits in the final circuit.
 
         Raises:
             ValueError: If StarConnectivity Placer and Router are used with non-star topologies.
@@ -238,7 +233,10 @@ def route_circuit(
         topology = nx.Graph(coupling_map if coupling_map is not None else self.settings.topology)
         circuit_router = CircuitRouter(topology, placer, router)
 
-        return circuit_router.route(circuit, iterations)
+        circuit, final_layout = circuit_router.route(circuit, iterations)
+        logger.info(f"The physical qubits used for the execution will be: {final_layout}")
+
+        return circuit.queue, final_layout, circuit.nqubits
 
     @staticmethod
     def optimize_gates(gate_list: list[gates.Gate]) -> list[gates.Gate]: