<[EMAIL PROTECTED]> wrote: ... > def p(a,b): > if list( a ) != sorted( list( a ) ): raise ValueError, "String not > ordered." > if not b: return [''] > return [i+j for i in list(a) for j in p(a,b-1)]
No need for 2/3 of the list(...) calls. sorted(a) and sorted(list(a)) will ALWAYS be the same sequence; "for i in a" and "for i in list(a)" will always iterate on the same sequence [as long as you're not changing a inside the iteration, which, in this case, you aren't]. Alex -- http://mail.python.org/mailman/listinfo/python-list
