Dump MIDI events using python-midi

md.py

# supply two command line arguments

import midi.sequencer.sequencer_alsa as S
import midi.sequencer
import sys
import select

sr = midi.sequencer.SequencerRead()
sr.subscribe_port(sys.argv[1],sys.argv[2])
p = select.poll()
sr.configure_poll(p)

while True:
    #S.client_poll_descriptors(sr.client)
    p.poll()
    e = S.event_input(sr.client)
    if not e:
        sys.stdout.write(".")
        continue
    print "flgs={} tag={} tick={} time={} type={} note={} dur={} offvel={} vel={} chan={} pos={} skewbase={} skewval={} queue={} qpartime={}".format(
        e.flags, e.tag, e.time.tick, e.time.time.tv_sec + 1e-9 * e.time.time.tv_nsec, 
        e.type, e.data.note.note, e.data.note.duration, e.data.note.off_velocity, e.data.note.velocity, 
        e.data.note.channel, e.data.queue.param.position, e.data.queue.param.skew.base, e.data.queue.param.skew.value,
        e.data.queue.queue, e.data.queue.param.time.time.tv_sec + 1e-9 * e.data.queue.param.time.time.tv_nsec )

What are those 2 arguments? Can you provide an example?