Vector Retrieval Service：擷取Doc

collection.fetch(
    ids: Union[str, List[str]],
    partition: Optional[str] = None,
    async_req: bool = False
) -> DashVectorResponse

import dashvector

client = dashvector.Client(
    api_key='YOUR_API_KEY',
    endpoint='YOUR_CLUSTER_ENDPOINT'
)
collection = client.get(name='quickstart')

doc_id = '1'
docs = collection.fetch(doc_id)
# 判斷fetch介面是否成功
if docs:
    print('fetch success')
    # 判斷fetch的doc是否存在，如果指定的ID不存在，則返回的output為空白
    if doc_id in docs:
        doc = docs[doc_id]
        print(doc.id)
        print(doc.vector)
        print(doc.fields)
    # 遍曆返回結果
    for id in docs:
        print(docs[id])

# 批量fetch
docs = collection.fetch(['1','2'])