Velocity Reviews > Random Pairing

# Random Pairing

John Hunter
Guest
Posts: n/a

 07-06-2004
>>>>> "Jared" == Jared <(E-Mail Removed)> writes:

Jared> For a tournament I'm making a random pairing generator. I
Jared> haven't quite figured out how to randomly pair yet though.
Jared> Here's what I have so far:

Assuming you have 100 players, you can shuffle the index vector and
use zip to create a sequence of pairs

>>> from random import shuffle
>>> ind = range(100)
>>> shuffle(ind)
>>> pairs = zip(ind[::2], ind[1::2])
>>> print pairs

[(3, 51), (88, 73), (41, 62), (14, 3, (90, 2), (58, 26), (72, 19), (77, 89), (0, 30), (74, 49), (95, 67), (92, 60), (86, 76), (27, 25), (65, 22), (96, 23), (66, 43), (57, 12), (59, 54), (70, 55), (82, 61), (64, 40), (16, 85), (31, 4, (78, 52), (39, 53), (17, 13), (99, 5), (45, 71), (4, 9), (97, 83), (8, 7), (15, 56), (42, 84), (94, 91), (75, 29), (33, 80), (68, 2, (21, 1), (10, 37), (18, 93), (98, 32), (50, 36), (44, 11), (34, 69), (24, 79), (6, 46), (20, 35), (63, 87), (81, 47)]
>>>

Jared
Guest
Posts: n/a

 07-06-2004
For a tournament I'm making a random pairing generator. I haven't
quite figured out how to randomly pair yet though. Here's what I have
so far:

from random import *
import string
import random

prompt1 = "Who is Player 1?\n"
p1 = raw_input(prompt1)

prompt2 = "Who is Player 2?\n"
p2 = raw_input(prompt2)

prompt3 = "Who is Player 3?\n"
p3 = raw_input(prompt3)

prompt4 = "Who is Player 4?\n"
p4 = raw_input(prompt4)
print (p1,p2,p3,p4)

#Randomly pair players
Players[p1,p2,p3,p4]
index = MOD(Random(<Seed>)%3
for i < 4
volume = Player[index]
print p1, "vs.", p2
print p3, "vs.", p4

while 1:
prompt5 = "Who won the in the first pairing?\n"
winner1 = raw_input(prompt5)
prompt6 = "Who won the in the second pairing?\n"
winner2 = raw_input(prompt6)
print winner1, "vs.", winner2
#/ if winner1 = v and winner2 = y
#/ print x, "vs.", z
#/ if winner1 = v and winner2 = z
#/ print x, "vs.", y
#/ if winner1 = v and winner2 = x
#/ print y, "vs.", z

#Pair the winner vs. the winner and the loser vs. the loser
y = raw_input(prompt5)#input didn't work

if str(y) == 'Exit' or str(y) == 'exit':
break

Harry George
Guest
Posts: n/a

 07-06-2004
http://www.velocityreviews.com/forums/(E-Mail Removed) (Jared) writes:

> For a tournament I'm making a random pairing generator. I haven't
> quite figured out how to randomly pair yet though. Here's what I have
> so far:
>
> from random import *
> import string
> import random
>
> prompt1 = "Who is Player 1?\n"
> p1 = raw_input(prompt1)
>
> prompt2 = "Who is Player 2?\n"
> p2 = raw_input(prompt2)
>
> prompt3 = "Who is Player 3?\n"
> p3 = raw_input(prompt3)
>
> prompt4 = "Who is Player 4?\n"
> p4 = raw_input(prompt4)
> print (p1,p2,p3,p4)
>
> #Randomly pair players
> Players[p1,p2,p3,p4]
> index = MOD(Random(<Seed>)%3
> for i < 4
> volume = Player[index]
> print p1, "vs.", p2
> print p3, "vs.", p4
>
>
> while 1:
> prompt5 = "Who won the in the first pairing?\n"
> winner1 = raw_input(prompt5)
> prompt6 = "Who won the in the second pairing?\n"
> winner2 = raw_input(prompt6)
> print winner1, "vs.", winner2
> #/ if winner1 = v and winner2 = y
> #/ print x, "vs.", z
> #/ if winner1 = v and winner2 = z
> #/ print x, "vs.", y
> #/ if winner1 = v and winner2 = x
> #/ print y, "vs.", z
>
> #Pair the winner vs. the winner and the loser vs. the loser
> y = raw_input(prompt5)#input didn't work
>
> if str(y) == 'Exit' or str(y) == 'exit':
> break

You may have good reasons for this architecture but one would normally
give it bit more substance:

1. A "model" in the model-view-controller sense, with objects for
players, matches, tiers, etc.

commandline as you show (even then it should be isolated from the
model), or picked up from a web CGI, or parsed from a spreadsheet
csv, or parsed from an XML, etc.

3. A compute engine to actually do the pairings. E.g., for initial
random pairings, random.shuffle, then take 2 at a time.
Afterwards, you seem to want to do winners with winners and losers
with losers, so we just have the same problem on two different
sequences.

4. A "view" to show the pairings, e.g., a website, or maybe an XMLRPC
service.

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