def get_vote_avg(cls):
avgCursor = cls.blogItemCollection.aggregate([{
'$group': {
'_id': '$source',
'avgVote': {
'$avg': "$vote"
}
}
}])
avgList = list(avgCursor)
avg = SON.to_dict(avgList[0])['avgVote']
return avg
def get_start_article_url(cls):
"""get the last article url from mongodb
算法是随机选取当前文章中被赞数大于平均值的一个文章的url
"""
# match = {'$group': {'_id': "$_id", 'vote': {'$max': "$vote"}}}
# max = cls.blogItemCollection.aggregate([match])
maxCursor = cls.blogItemCollection.find({}, {
"vote": 1,
'_id': 0
}).sort('vote', -1).limit(1)
maxVoteList = list(maxCursor)
if maxVoteList.__len__() <= 0:
# 数据库中尚未有数据
log.msg("there isn't any article in mongodb", level=log.DEBUG)
return None
max = SON.to_dict(maxVoteList[0])['vote']
avg = math.floor(cls.get_vote_avg())
articlesCursor = cls.blogItemCollection.find({"vote": {'$lte': max, '$gte': avg}}, {"id": 1, "vote": 1, '_id': 0})\
.sort('vote', -1).limit(3)
articlesList = list(articlesCursor)
index = randint(0, articlesList.__len__() - 1)
article = SON.to_dict(articlesList[index])
return article['id']