我正在构建一个网站，其中从数据库中随机选择两个音乐视频进行投票。我希望得到一个算法，该算法将继续为用户挑选独特的匹配，排除他们过去拥有的匹配，但为新的匹配替换视频。
2、解决方案
我的解决方案是查询来自数据存储的所有视频并随机选择一个。我还查询了用户的过去投票/匹配，并将它转换为一个列表，以便在不运行多次查询的情况下对其进行操作。使用随机视频，我用一个循环找到一个不在前一匹配列表中的第二个视频。如果没有找到视频，程序会从视频列表中删除随机选项，然后选择一个新的样本并再次运行搜索。
代码示例：
class MainHandler(views.Template):
def post(self):
# NOTE: we are posting genre and state.
user = self.user_check()
self.videos = models.videos.Videos.fetch_featured()
try:
random.sample(self.videos,2)
if user:
self.user_votes = models.voting.Voting.query_by_user(user.key)
if self.user_votes != None:
self.user_votes = [[x.video_one,x.video_two] for x in self.user_votes]
page_vids = False
while page_vids == False and len(self.videos)>1:
rand_vid = random.choice(self.videos)
page_vids = self.find_match(rand_vid)
self.videos.remove(rand_vid)
else:
page_vids = random.sample(self.videos,2)
else:
page_vids = random.sample(self.videos,2)
except:
page_vids = None
def find_match(self, rand_vid):
i =0
while i < len(self.videos):
if rand_vid.key != self.videos[i].key and ([rand_vid.key,self.videos[i].key] not in self.user_votes and [self.videos[i].key, rand_vid.key] not in self.user_votes):
return [rand_vid,self.videos[i]]
i+=1
return False
class Videos(ndb.Model):
acc_key = ndb.KeyProperty()
musician_key = ndb.KeyProperty()
musician_name = ndb.StringProperty()
embed_link = ndb.StringProperty()
genre_tag = ndb.StringProperty()
video_title = ndb.StringProperty()
featured = ndb.BooleanProperty(default = False)
likes_count = ndb.IntegerProperty()
video_added = ndb.DateTimeProperty(auto_now_add = True)
@classmethod
def query_by_account(cls, acc_key):
return cls.query(cls.acc_key == acc_key).fetch()
@classmethod
def fetch_featured(cls):
return cls.query(cls.featured == True).fetch(100)
class Voting(ndb.Model):
voter_acc_key = ndb.KeyProperty()
voter_type = ndb.StringProperty()
video_one = ndb.KeyProperty()
video_one_artist_key = ndb.KeyProperty()
video_two = ndb.KeyProperty()
video_two_artist_key = ndb.KeyProperty()
voter_choice = ndb.KeyProperty()
video_set_check = ndb.KeyProperty(repeated = True)
voter_ip = ndb.StringProperty()
vote_time = ndb.DateTimeProperty(auto_now_add = True)
@classmethod
def query_by_user(cls, acc_key):
return cls.query(cls.voter_acc_key == acc_key).fetch(2000)
