Code works fine except...

[John Machin]

On May 4, 12:36 pm, Ross <ross.j... at gmail.com> wrote:
> For the past couple weeks, I've been working on an algorithm to
> schedule tennis leagues given court constraints and league
> considerations (i.e. whether it's a singles or a doubles league). Here
> were my requirements when I was designing this algorithm:
>
> -Each player plays against a unique opponent each week.
> -Similarly, in a doubles league, each player plays with a unique
> partner each week.
> -Each player gets a fair number of bye weeks (i.e. the player with the
> most bye weeks will have no more than one bye week than the player
> with the least number of bye weeks)
>
> I'm very close to arriving at my desired solution, but I have one
> glaring flaw. When I have an even number of players sign up for my
> league and there are court constraints, my current algorithm gives the
> first player in my league a bye week every single week. I'll post my
> code below and see how you guys think I should add to/ amend my code.
>
> def round_robin(players, rounds):
>     if len(players)%2:
>         players.insert(0, None)
>     mid = len(players)//2
>     for i in range(rounds):
>         yield zip(players[:mid], players[mid:])
>         players = players[0:1] + players[mid:mid+1] + players[1:mid-1] +
> players[mid+1:] + players[mid-1:mid]
>
> def test_round_robin(players, rounds, courts, doubles = False):
>     players = range(players)

DON'T change the type/contents/meaning of a variable name like that.
E.g. use "nthings" for a number of things and "things" for a
collection of things.

>     for week in round_robin(players,rounds,courts):

The round_robin() function has only TWO arguments. This code won't
even run.

When you document neither your data structures nor what your functions
are intended to do, the last hope for somebody trying to make sense of
your code is to give meaningful names to your variables. "week" and
"doubles_week" are NOT meaningful.

>             if doubles == True:

Bletch. s/ == True//


>                     doubles_week = len(week)/2.0

I doubt very much that using floating point is a good idea here.

>                     byes = doubles_week - courts
>                     if byes == 0:
>                             bye_list = []
>                     else:
>                             bye_list = week[::int(round(1.072*(courts/byes)+1.08))]

The derivation of the constants 1.072 and 1.08 is .... what?

>                     playing = [u for u in week if u not in bye_list]
>                     midd = len(playing)//2
>                     doub_sched = zip(playing[:midd], playing[midd:])
>                     print doub_sched, bye_list
>             else:
>                     byes = len(week)- courts
>                     if byes == 0:
>                             bye_list = []
>                     else:
>                             bye_list = week[::int(round(1.072*(courts/byes)+1.08))]
>                     playing = [u for u in week if u not in bye_list]
>                     print playing, bye_list