PynamoDB Error for Local Secondary Index: ValueError('Table table_4 has no index: key1_index',)

I am new to pynamodb and I'm trying to query on LSI (already defined in dynamodb main table) and getting the following Exception.

'exception': ValueError('Table table_4 has no index: key1_index',)

UseCase: i wanted to query on LSI on hash_key only, as I have provided default value for key1 (range_key) and wanted to fetch the sorted data on the basis of key1.

LSI Model

class LSI_Index(LocalSecondaryIndex):
    id = UnicodeAttribute(hash_key=True)
    key1 = NumberAttribute(default=int(time.time()), range_key=True)

    class Meta:
        index = "key1-Index"
        projection = IncludeProjection(['id', 'key1', 'key2'])

Main Table Model

class MainModel(Model):
    id = UnicodeAttribute(hash_key=True)
    key2 = UnicodeAttribute(range_key=True, default='')
    key1 = NumberAttribute(default=int(time.time()))
    key1_index = LSI_Index()   # LSI

    class Meta:
        .....

Repository Method Code

    def read_by_LSI(cls, id):
    try:
        data = []
        iterator = MainModel.key1_index.query(hash_key=id,limit=1,scan_index_forward=False, consistent_read=True)
        for item in iterator:
            data.append(json.loads(json_dumps(item)))
        return data

DynamoDB Main Table Description:

{
    "Table": {
        "AttributeDefinitions": [
            {
                "AttributeName": "id",
                "AttributeType": "S"
            },
            {
                "AttributeName": "key1",
                "AttributeType": "N"
            }
        ],
        "TableName": "table_4",
        "KeySchema": [
            {
                "AttributeName": "id",
                "KeyType": "HASH"
            }
        ],
        "TableStatus": "ACTIVE",
        "CreationDateTime": 1647447620.911,
        "ProvisionedThroughput": {
            "LastIncreaseDateTime": 0.0,
            "LastDecreaseDateTime": 0.0,
            "NumberOfDecreasesToday": 0,
            "ReadCapacityUnits": 10,
            "WriteCapacityUnits": 5
        },
        "TableSizeBytes": 779,
        "ItemCount": 7,
        "TableArn": "arn:aws:dynamodb:ddblocal:000000000000:table/table_4",
        "LocalSecondaryIndexes": [
            {
                "IndexName": "key1-Index",
                "KeySchema": [
                    {
                        "AttributeName": "id",
                        "KeyType": "HASH"
                    },
                    {
                        "AttributeName": "key1",
                        "KeyType": "RANGE"
                    }
                ],
                "Projection": {
                    "ProjectionType": "INCLUDE",
                    "NonKeyAttributes": [
                        "key2",
                        "key1",
                    ]
                },
                "IndexSizeBytes": 779,
                "ItemCount": 7,
                "IndexArn": "arn:aws:dynamodb:ddblocal:000000000000:table/table_4/index/key1-Index"
            }
        ]
   }
}

Please tell me where I am doing wrong as I am not able to debug the issue. Thanks in advance.!!

So basically, when defining LSI Model in pynamodb, please make sure the Meta class attribute names are the same as mentioned in the doc - https://pynamodb.readthedocs.io/en/latest/indexes.html

In the above instance, I did the following mistake due to which I was getting ValueError('table table_4 doesn't have key1_index') Exception.

In MetaClass of LSI_Model Class, I used the wrong attribute name 'index' instead of 'index_name'. I have updated the code and now it works fine.

class LSI_Index(LocalSecondaryIndex):
id = UnicodeAttribute(hash_key=True)
key1 = NumberAttribute(default=int(time.time()), range_key=True)

class Meta:
    index_name = "key1-Index"
    projection = IncludeProjection(['id', 'key1', 'key2'])

Note: LSI Meta Class attributes should be named as follows (mentioned in doc):

1. index_name
2. projection and so on..