I had a request recently to provide a count of devices assigned to a particular System organizer, per Group organizer.  An example:

Group1 has 2 Routers that are each in the System organizer of "Routers", and 4 Switches each in the System organizer of "Switches"

Group2 has 1 Router in the System organizer of "Routers", and one Server in the System organizer of "Servers"

I needed a zendmd script that would output a list like this:

Group1:

Routers: 2

Switches: 4

Group2:

Routers: 1

Servers: 1

and so on.

I posed this question to the irc chat room and rmatte came up with this

for g in dmd.Groups.getSubOrganizers():
groupcount = {}
for d in g.getSubDevices():
  if d.getSystemNames():
   try:
    groupcount[d.getSystemNames()[0].split('/')[1]] = groupcount[d.getSystemNames()[0].split('/')[1]] + 1
   except KeyError:
    groupcount[d.getSystemNames()[0].split('/')[1]] = 1
print "%s:" % (g.id)
for a, b in groupcount.iteritems():
  print "   %s: %s" % (a, b)
print ""

This works perfectly for my needs.  With rmatte's blessing, I'm dropping it here so it can help out some other folks as well.