如何使用boto3 python库在dynamodb事务中执行条件写入

import boto3
from boto3.dynamodb.conditions import Attr

dynamodb = boto3.client('dynamodb')

def perform_transaction(table_name, key, condition, update_expression):
    response = dynamodb.transact_write_items(
        TransactItems=[
            {
                'Update': {
                    'TableName': table_name,
                    'Key': key,
                    'ConditionExpression': condition,
                    'UpdateExpression': update_expression
                }
            }
        ]
    )
    return response

table_name = 'your_table_name'
key = {
    'primaryKey': {'S': 'your_primary_key_value'}
}
condition = Attr('attributeName').eq('condition_value')
update_expression = 'SET attributeName = :newValue'
response = perform_transaction(table_name, key, condition, update_expression)

if 'Responses' in response:
    print("写入成功")
else:
    print("写入失败")