import tables
import numpy

class RawSample(tables.IsDescription):
    timestamp = tables.UInt64Col()
    voltage   = tables.UInt16Col(shape = 3)
    current   = tables.UInt16Col(shape = 3)

h5file = tables.openFile("test.h5", mode = "w", title = "Test")
group = h5file.createGroup("/", "raw", "Raw Data")
table = h5file.createTable(group, "nilm1", RawSample, "NILM 1")

print repr(h5file)

# write rows