Only count non-identity gate in Qiskit

  start = time.time()

  comp = trotter_circ(q, ham_op.oplist, nbSteps)

  end = time.time()

  print("n_qubits =", nbQubits, "; n instructions =", comp.depth(), "; Kernel eval time:", end - start, " [secs]")

  ops_count = comp.count_ops()

  num_gates = 0

  # Count gates except identity

  for gate_name in ops_count:

    if gate_name != "id":

      num_gates += ops_count[gate_name]

  print("n_qubits =", nbQubits, "; n instructions =", num_gates, "; Kernel eval time:", end - start, " [secs]")