Arnaud Delobelle <arno...@googlemail.com> writes: > Gilles Ganault <nos...@nospam.com> writes: > >> On Fri, 22 Jan 2010 13:17:44 +0100, Gilles Ganault <nos...@nospam.com> >> wrote: >>>To avoid users from creating login names that start with digits in >>>order to be listed at the top, I'd like to sort the list differently >>>every minute so that it'll start with the next letter, eg. display the >>>list from A...Zdigits the first time, then B...ZAdigits, etc. >> >> Thanks everyone for the great feedback. I ended up using >> - a list instead of a dictionary to hold the list of names >> - use the random library to pick a character from which to start >> listing names (simpler than saving the next letter into a file, and >> starting from this the next time the loop is gone through) >> >> For those interested, here's some working code: >> >> ========== >> import random >> >> connected = >> ["_test","-test","0test","1test","Aa","Aab","Bb","Bbbbb","Cc","Ccaaaaaa"] >> connected.sort() >> >> #Fill list with non-duplicate first letter of all items >> characters=[] >> for name in connected: >> char = name[0] >> #if this character not in list, add to array >> if not char in characters: >> characters.append(char) > > characters = list(set(name[0] for name in connected)) > >> #Pick a random character from which to start iterating >> index = random.randint(0,len(characters)-1) >> startch = characters[index] > > startch = random.choice(characters) > >> print "Will start from %s" % startch >> >> #Go through list starting with items that start with 'starch', and >> rotate from beginning >> result = [name for name in connected if name[0] >= startch] + [name >> for name in connected if name[0] < startch]
I forgot this line: result = sorted(connected, key=lambda name: name[0] < startch) This takes advantage of the fact that timsort is stable. So you could do it like this, assuming connected is sorted: characters = list(set(name[0] for name in connected)) startch = random.choice(characters) result = sorted(connected, key=lambda name: name[0] < startch) If connected is not sorted, you could replace the last line with: result = sorted(connected, key=lambda name: (name[0] < startch, name)) -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
