from qiskit import QuantumCircuit, QuantumRegister
from qiskit.circuit.gate import Gate
from qiskit.circuit.library.standard_gates import HGate
from qiskit import transpile
from qiskit_aer import Aer


class Custom(Gate):
    def __init__(self, label=None):
        super().__init__("p", 1, [], label=label)

    def _define(self):
        q = QuantumRegister(1, "q")
        qc = QuantumCircuit(q, name=self.name)
        qc._append(HGate(), [q[0]], [])
        self.definition = qc


qc = QuantumCircuit(1)
qc.append(Custom(), [0])
qc.measure_all()

backend_sim = Aer.get_backend("qasm_simulator")
transpiled = transpile(qc, backend_sim)
result_sim = backend_sim.run(transpiled, shots=10).result()