You're making it more complicated than it needs to. Also, you first used binnum then binum, and you didn't define binsum.
It could easily be done like this:
binnum = raw_input("Please enter a binary number: ")
decnum = 0
rank = 1
for i in reversed(binnum):
decnum += rank * int(i)
rank *= 2
Moos
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
