This is a little better and works:
row = list(system.dataset.toPyDataSet(dataset2)[0])
dataset1 = system.dataset.addRow(dataset1, dataset1.rowCount, row)
This is a little better and works:
row = list(system.dataset.toPyDataSet(dataset2)[0])
dataset1 = system.dataset.addRow(dataset1, dataset1.rowCount, row)