groups.py

def chunk(list, n):
  """Breaks a list into chunks of size n."""
  return [ list[i:i+n] for i in range(0, len(list), n)]

def balanceGroups(groups):
  """Balances a list of lists, so they are roughly equally sized."""
  numPlayers = sum([len(group) for group in groups])
  minGroupSize = int(numPlayers/len(groups))
  groupsArr = list(enumerate(groups))

  for i, group in groupsArr:
    while(len(group) < minGroupSize):
      for j, groupSteal in groupsArr:
        if (i != j) and len(groupSteal) > minGroupSize:
          group.append(groupSteal.pop())

  return [group for group in groups]

def makeGroups(players, groupSize):
  """Makes even-ish groups of size groupSize and return an array of the players."""
  if len(players) == 1:
    return []

  groups = chunk(players, groupSize)
  if len(groups) == 1:
    return groups

  return balanceGroups(groups)



print(makeGroups([1,2,3,4,5,6,7,8,9], 4))