Python 使用正则表达式进行MongoDB条件查询

def extract_qq(batch_num, platform, profile_collection, path):
    """
    :param path: qq号导出文件路径
    :param platform: 平台
    :param profile_collection: 数据库集合
    :type batch_num: int
    """
    qq_file = open(path, 'w')
    key = "name" if platform == "PAC" else "_id"
    cnt = profile_collection.count({key: {"$regex": "1_[0-9]{5,}"}})
    print("cnt = %d" % cnt)
    length = int(math.ceil(cnt / float(batch_num)))
    # 数据库查询QQ号，导出到本地文件
    for x in xrange(0, length):
        print("%d/%d" % (x, length))
        cursor = profile_collection.find({key: {"$regex": "1_[0-9]{5,}"}}, {key: 1}).limit(batch_num).skip(x*batch_num)
        for user_profile in cursor:
            qq_file.write(user_profile.get(key).split("1_")[1] + "\n")
        cursor.close()
    qq_file.close()