qiskit/dagcircuit/dagcircuit.py
def qubits(self):
        """Return a list of qubits as (QuantumRegister, index) pairs."""
        return [(v, i) for k, v in self.qregs.items() for i in range(v.size)]
def qubits(self):
        """Return a list of qubits as (QuantumRegister, index) pairs."""
        return [(v, i) for k, v in self.qregs.items() for i in range(v.size)]
Return a list of qubits as (QuantumRegister, index) pairs.