from collections import deque 
import random 
def build_schedule(_teamarr): 
  scheduleobj = dict.fromkeys(range(1,20)) 
  fixpos = _teamarr[0] 
  ring = _teamarr[1:] 
  ring = deque(ring) 
  #前半赛程，1-19轮(round) 
  for round in range(1,20): 
    #第1支球队不动，再加上轮转(rotate)的环 
    teams = [fixpos] + list(ring) 
    #切成2列，左边主队，右边客队 
    home, away = teams[:len(teams)/2],teams[len(teams)/2:] 
    away = away[::-1] 
    #随机打乱主客队 
    scheduleobj[round] = [(x,y) if random.random()>=0.5 else (y,x) for x,y in zip(home,away)] 
    ring.rotate(1) 
  #后半赛季对阵跟前半赛季一样，但主客队对调 
  for round in range(20,39): 
    scheduleobj[round] = [(y,x) for x,y in scheduleobj[round-19]] 
  return scheduleobj 
 
if __name__ == '__main__': 
  teamarr = [u'曼联', u'阿斯顿维拉', u'切尔西', u'西汉姆', u'富勒姆', 
        u'热刺', u'利物浦', u'南安普顿', u'埃弗顿', u'诺维奇', 
        u'纽卡斯尔', u'曼城', u'斯托克城', u'桑德兰', u'水晶宫', 
        u'西布罗姆维奇', u'阿森纳', u'赫尔城', u'卡迪夫城', u'斯旺西'] 
  scheduleobj = build_schedule(teamarr) 
  print u'---联赛第1轮---' 
  for h,a in scheduleobj[1]: 
    print u'{}-{}'.format(h,a) 
 
  print u'---联赛第2轮---' 
  for h,a in scheduleobj[2]: 
    print u'{}-{}'.format(h,a)