I'm still learning python. I just wrote this method to determine if a player has won a game of tic-tac-toe yet, given a board state like:'[['o','x','x'],['x','o','-'],['x','o','o']]'

def hasWon(board):
  players = ['x', 'o']
  for player in players:
    for row in board:
      if row.count(player) == 3:
        return player
    top, mid, low = board
    for i in range(3):
      if [ top[i],mid[i],low[i] ].count(player) == 3:
        return player
    if [top[0],mid[1],low[2]].count(player) == 3:
        return player
    if [top[2],mid[1],low[0]].count(player) == 3:
        return player
  return None

It occurred to me that I check lists of 3 chars several times and could refactor the checking to its own method like so:

def check(list, player):
  if list.count(player) == 3:
    return player

...but then realized that all that really does is change lines like:

 if [ top[i],mid[i],low[i] ].count(player) == 3:
    return player

to:

  if check( [top[i],mid[i],low[i]], player ):
    return player

...which frankly doesn't seem like much of an improvement. Do you see a better way to refactor this? Or in general a more Pythonic option? I'd love to hear it!