multiple discontinued ranges

[xoff]

I was wondering what the best method was in Python programming for 2
discontinued ranges. e.g. I want to use the range 3 to 7 and 17 to 23.
Am I obliged to use 2 for loops defining the 2 ranges like this:

for i in range (3,7):
 do bla
for i in range (7,17):
 do bla

or is there a more clever way to do this?