qiskit/transpiler/coupling.py
def add_edge(self, src, dst):
        """
        Add directed edge to coupling graph.

        src (int): source physical qubit
        dst (int): destination physical qubit
        """
        if src not in self.physical_qubits:
            self.add_physical_qubit(src)
        if dst not in self.physical_qubits:
            self.add_physical_qubit(dst)
        self.graph.add_edge(src, dst)
        self._dist_matrix = None
def add_edge(self, src, dst):
        """
        Add directed edge to coupling graph.

        src (int): source physical qubit
        dst (int): destination physical qubit
        """
        if src not in self.physical_qubits:
            self.add_physical_qubit(src)
        if dst not in self.physical_qubits:
            self.add_physical_qubit(dst)
        self.graph.add_edge(src, dst)
        self._dist_matrix = None
Add directed edge to coupling graph.

        src (int): source physical qubit
        dst (int): destination physical qubit