从后面的3个字符后添加“，” - python

我只是想在每3个字符之间显示一个“，”! 我尝试了: players = ','.join([player[i:i+3] for i in range(0, len(player), 3)]) rankedplayers = ','.join([ranked[i:i+3] for i in range(0, len(ranke […]