qiskit/circuit/quantumcircuit.py
def _check_qargs(self, qargs):
        """Raise exception if a qarg is not in this circuit or bad format."""
        if not all(isinstance(i, tuple) and
                   isinstance(i[0], QuantumRegister) and
                   isinstance(i[1], int) for i in qargs):
            raise QiskitError("qarg not (QuantumRegister, int) tuple")
        if not all(self.has_register(i[0]) for i in qargs):
            raise QiskitError("register not in this circuit")
        for qubit in qargs:
            qubit[0].check_range(qubit[1])
def _check_qargs(self, qargs):
        """Raise exception if a qarg is not in this circuit or bad format."""
        if not all(isinstance(i, tuple) and
                   isinstance(i[0], QuantumRegister) and
                   isinstance(i[1], int) for i in qargs):
            raise QiskitError("qarg not (QuantumRegister, int) tuple")
        if not all(self.has_register(i[0]) for i in qargs):
            raise QiskitError("register not in this circuit")
        for qubit in qargs:
            qubit[0].check_range(qubit[1])
Raise exception if a qarg is not in this circuit or bad format.