Python League Generator

Question

I would like to write the Fiestire League generator in python, but I cannot. Here are the details:

There is a dynamic list of teams like teams = ["Team1", "Team2", "Team3", "Team4"] . How can I create a fixture_weekx list from a list of commands? For instance:

 fixture_week1 = ["Team1", "Team2", "Team3", "Team4"] fixture_week2 = ["Team1", "Team3", "Team2", "Team4"] fixture_week2 = ["Team1", "Team4", "Team2", "Team3"] #Return matches: fixture_week1 = ["Team2", "Team1", "Team4", "Team3"] fixture_week2 = ["Team3", "Team1", "Team4", "Team2"] fixture_week2 = ["Team4", "Team1", "Team3", "Team2"] 

Any idea?

Answer 1

The fixture schedule is a well-known problem. This is a python implementation of the algorithm given at: http://en.wikipedia.org/wiki/Round-robin_tournament

 # generation code - for cut and paste import operator def fixtures(teams): if len(teams) % 2: teams.append('Day off') # if team number is odd - use 'day off' as fake team rotation = list(teams) # copy the list fixtures = [] for i in range(0, len(teams)-1): fixtures.append(rotation) rotation = [rotation[0]] + [rotation[-1]] + rotation[1:-1] return fixtures # demo code teams = ["Team1", "Team2", "Team3", "Team4", "Team5"] # for one match each - use this block only matches = fixtures(teams) for f in matches: print zip(*[iter(f)]*2) # if you want return matches reverse_teams = [list(x) for x in zip(teams[1::2], teams[::2])] reverse_teams = reduce(operator.add, reverse_teams) # swap team1 with team2, and so on .... #then run the fixtures again matches = fixtures(reverse_teams) print "return matches" for f in matches: print f 

This generates the output:

 [('Team1', 'Day off'), ('Team2', 'Team5'), ('Team3', 'Team4')] [('Team1', 'Team5'), ('Day off', 'Team4'), ('Team2', 'Team3')] [('Team1', 'Team4'), ('Team5', 'Team3'), ('Day off', 'Team2')] [('Team1', 'Team3'), ('Team4', 'Team2'), ('Team5', 'Day off')] [('Team1', 'Team2'), ('Team3', 'Day off'), ('Team4', 'Team5')] 

Answer 2

I wanted to comment that the code from @MariaZverina does not quite work. I tried it as is, but I did not get the right pairs. The modification I made below works with its code. The difference is that I make a combination of the rainbow style of each fixture, taking the first half of the fixture f with the reverse second half.

 # demo code teams = ["Team1", "Team2", "Team3", "Team4", "Team5"] # for one match each - use this block only matches = fixtures(teams) for f in matches: # This is where the difference is. # I implemented "rainbow" style pairing from each fixture f # In other words: # [(f[0],[f[n-1]), (f[1],f[n-2]), ..., (f[n/2-1],f[n/2])], # where n is the length of f n = len(f) print zip(f[0:n/2],reversed(f[n/2:n])) 

Answer 3

The code from @MariaZverina did not work, I also implemented this code using Round-robin_tournament:

 teams = ["Team1", "Team2", "Team3", "Team4", "Team5", "Team6"] if len(teams) % 2: teams.append('Day off') n = len(teams) matchs = [] fixtures = [] return_matchs = [] for fixture in range(1, n): for i in range(n/2): matchs.append((teams[i], teams[n - 1 - i])) return_matchs.append((teams[n - 1 - i], teams[i])) teams.insert(1, teams.pop()) fixtures.insert(len(fixtures)/2, matchs) fixtures.append(return_matchs) matchs = [] return_matchs = [] for fixture in fixtures: print fixture 

Output:

 [('Team1', 'Team6'), ('Team2', 'Team5'), ('Team3', 'Team4')] [('Team1', 'Team5'), ('Team6', 'Team4'), ('Team2', 'Team3')] [('Team1', 'Team4'), ('Team5', 'Team3'), ('Team6', 'Team2')] [('Team1', 'Team3'), ('Team4', 'Team2'), ('Team5', 'Team6')] [('Team1', 'Team2'), ('Team3', 'Team6'), ('Team4', 'Team5')] [('Team6', 'Team1'), ('Team5', 'Team2'), ('Team4', 'Team3')] [('Team5', 'Team1'), ('Team4', 'Team6'), ('Team3', 'Team2')] [('Team4', 'Team1'), ('Team3', 'Team5'), ('Team2', 'Team6')] [('Team3', 'Team1'), ('Team2', 'Team4'), ('Team6', 'Team5')] [('Team2', 'Team1'), ('Team6', 'Team3'), ('Team5', 'Team4')]