>> 1. Re: List comprehension question (Richard D. Moores) >>> ?: def proper_divisors_sum(n):
>>> A few questions--noting, of course, that I'm not reading this with >>> an eye toward performance, which it seems you are, but these occur >>> to me: Tim Peters had a beautiful little version of divisors at http://stackoverflow.com/questions/1010381/python-factorization A modified version of this is part of the python CAS system sympy (sympy.org). >From sympy you simply do: >>> from sympy import divisors >>> list(divisors(256)) [1, 2, 4, 8, 16, 32, 64, 128, 256] So your proper divisors would just be sum(divisors(n)) - n. The divisors function there is in the ntheory/factor_.py file. /c _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
