python – DynamoDB – 如何查询嵌套属性boto3

以下是此查询的代码：

from __future__ import print_function # Python 2/3 compatibility
import boto3
import json
import decimal
from boto3.dynamodb.conditions import Key,Attr

# Helper class to convert a DynamoDB item to JSON.
class DecimalEncoder(json.JSONEncoder):
    def default(self,o):
        if isinstance(o,decimal.Decimal):
            return str(o)
        return super(DecimalEncoder,self).default(o)

dynamodb = boto3.resource('dynamodb',region_name='us-west-2',endpoint_url="http://localhost:8000")

table = dynamodb.Table('Movies')

print("Movies from 1992 - titles A-L,with genres and lead actor")

response = table.query(
    ProjectionExpression="#yr,title,info.genres,info.actors[0]",ExpressionAttributeNames={ "#yr": "year" },# Expression Attribute Names for Projection Expression only.
    KeyConditionExpression=Key('year').eq(1992) & Key('title').between('A','L')
)

for i in response[u'Items']:
    print(json.dumps(i,cls=DecimalEncoder))

示例响应项是

{
    "title": "Juice","year": "1992","info": {
        "actors": [
            "Omar Epps"
        ],"genres": [
            "Crime","Drama","Thriller"
        ]
    }
}

该表有两个关键属性’title’和’year’以及嵌套属性’info’.我想要做的是查询数据库并按流派过滤电影,例如获取所有戏剧电影.我不知道如何做到这一点,因为类型键嵌套在内部信息.

我试图从1992年开始拍摄所有的戏剧电影,但它却一片空白.

response = table.query(
    KeyConditionExpression=Key('year').eq(1992),FilterExpression=Attr('info.genres').eq('Drama')
)

如何使用嵌套的info属性正确过滤此查询？