Arun Srinivasan wrote: > I'm trying to learn Python, and I decided to try kata 2 </> from the > CodeKate website. It's basically just a challenge to implement a > binary search in different ways. > > I wrote an implementation that works, but I'm confused as to why. > > def chop(search_int, sorted_list): > if len(sorted_list) == 1 or 2: Yet another way to express that is:
if 1 <= len(sorted_list) <= 2: > for x in sorted_list: > if x == search_int: > return sorted_list.index(x) > return -1 > > midpoint = (len(sorted_list) - 1) / 2 > mp_value = sorted_list[midpoint] > > if mp_value == search_int: > return midpoint > elif mp_value > search_int: > return chop(search_int, sorted_list[:midpoint]) > else: > return chop(search_int, sorted_list[midpoint + 1:]) > > Basically, it only returns the index if it matches in the if statement > at the beginning of the function, but since that is limited to lists > of length 2 or 1, why doesn't it return only 0 or 1 as the index? I > think there is something about recursion here that I'm not fully > comprehending. > > > > ------------------------------------------------------------------------ > > _______________________________________________ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > -- Bob Gailer 919-636-4239 Chapel Hill, NC _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor