head for grouped data - looking for best practice

[Harald Massa]

Old, very old informatical problem: I want to "print" grouped data with 
head information, that is:


eingabe=[
("Stuttgart","70197","Fernsehturm","20"),
("Stuttgart","70197","Brotmuseum","123"),
("Stuttgart","70197","Porsche","123123"),
("Leipzig","01491","Messe","91822"),
("Leipzig","01491","Schabidu","9181231"),
]

shall give: ( Braces are not important...)

'Stuttgart', '70197'
--data-- ('Fernsehturm', '20')
--data-- ('Brotmuseum', '123')
--data-- ('Porsche', '123123')
Leipzig', '01491'
--data-- ('Messe', '91822')
--data-- ('Schabidu', '9181231')

my first approach was:


from itertools import groupby
from operator import itemgetter

for key, bereich in groupby(eingabe,itemgetter(0)):
    print "Area:",key
    headnotprinted=True
    for data in bereich:
        if headnotprinted:
            headnotprinted=False
            print "additional head info", data[1]
        print "--data--", data[2:]

leading to:

Area: Stuttgart
additional head info 70197
--data-- ('Fernsehturm', '20')
--data-- ('Brotmuseum', '123')
--data-- ('Porsche', '123123')
Area: Leipzig
additional head info 01491
--data-- ('Messe', '91822')
--data-- ('Schabidu', '9181231')


which is quite what I expected. But ... 
        if headnotprinted:
            headnotprinted=False
            print "additional head info", data[1]

REALLY looks patched, not programmed.

my second try was:


def getdoublekey(row):
    return row[0:2]

for key, bereich in groupby(eingabe,getdoublekey):
    print "Area:",key
    for data in bereich:
        print "--data--", data[2:]

which indeed leeds to the expected result, while looking less "hacky" .. 
on the other hand side, that "getdoublekey" ist not very flexible; when 
doing the same with 3 Columns forming the head information, I have to 
define the next function...

gettriplekey(row):
    return (row[1], row[0], ---yadda yadda yadda

so, what is the best recommended practice for this usual problem within 
Python?

Harald