old_contents: import match_stats
  
  
  def schedule_check(matches):
      print '{0} matches total'.format(len(matches))
      match_counter, opponents, collisions = match_stats.match_statistics(matches)
      all_teams = set(match_counter.iterkeys())
      for team, matches in match_counter.iteritems():
          print '{0}: {1} matches, missed opponents: {2}'.format(team, matches, ', '.join(all_teams - opponents[team] - {team}))
          if team in collisions:
              print '\t{0} DO have a match collision'.format(team)
  
new_contents: import match_stats
  import sys
  
  
  def schedule_check(matches):
      print >>sys.stderr, '{0} matches total'.format(len(matches))
      match_counter, opponents, collisions = match_stats.match_statistics(matches)
      all_teams = set(match_counter.iterkeys())
      for team, matches in match_counter.iteritems():
          print >>sys.stderr, '{0}: {1} matches, missed opponents: {2}'.format(team, matches, ', '.join(all_teams - opponents[team] - {team}))
          if team in collisions:
              print >>sys.stderr, '\t{0} DO have a match collision'.format(team)
  
subject: Make check messages print to stderr