用于google云数据存储的asyncio python客户端
gcloud-aio-datastore的Python项目详细描述
安装
$ pip install --upgrade gcloud-aio-datastore
用法
我们仍在进行文档工作；目前，这将有助于您 开始时间：
fromgcloud.aio.datastoreimportDatastorefromgcloud.aio.datastoreimportDirectionfromgcloud.aio.datastoreimportFilterfromgcloud.aio.datastoreimportGQLQueryfromgcloud.aio.datastoreimportKeyfromgcloud.aio.datastoreimportPathElementfromgcloud.aio.datastoreimportPropertyFilterfromgcloud.aio.datastoreimportPropertyFilterOperatorfromgcloud.aio.datastoreimportPropertyOrderfromgcloud.aio.datastoreimportQueryfromgcloud.aio.datastoreimportValueds=Datastore('my-gcloud-project','/path/to/creds.json')key1=Key('my-gcloud-project',[PathElement('Kind','entityname')])key2=Key('my-gcloud-project',[PathElement('Kind','entityname2')])# batched lookupsentities=awaitds.lookup([key1,key2])# convenience functions for any datastore mutationsawaitds.insert(key1,{'a_boolean':True,'meaning_of_life':41})awaitds.update(key1,{'a_boolean':True,'meaning_of_life':42})awaitds.upsert(key1,{'animal':'aardvark'})awaitds.delete(key1)# or build your own mutation sequences with full transaction supporttransaction=awaitds.beginTransaction()try:mutations=[ds.make_mutation(Operation.INSERT,key1,properties={'animal':'sloth'}),ds.make_mutation(Operation.UPSERT,key1,properties={'animal':'aardvark'}),ds.make_mutation(Operation.INSERT,key2,properties={'animal':'aardvark'}),]awaitds.commit(transaction,mutations=[mutation])exceptException:awaitds.rollback(transaction)# support for partial keyspartial_key=Key('my-gcloud-project',[PathElement('Kind')])# and ID allocation or reservationallocated_keys=awaitds.allocateIds([partial_key])awaitds.reserveIds(allocated_keys)# query supportproperty_filter=PropertyFilter(prop='answer',operator=PropertyFilterOperator.EQUAL,value=Value(42))property_order=PropertyOrder(prop='length',direction=Direction.DESCENDING)query=Query(kind='the_meaning_of_life',query_filter=Filter(property_filter),order=property_order)results=awaitds.runQuery(query,session=s)# alternatively, query support using GQLgql_query=GQLQuery('SELECT * FROM the_meaning_of_life WHERE answer = @answer',named_bindings={'answer':42})results=awaitds.runQuery(gql_query,session=s)
自定义子类
gcloud-aio-datastore提供类接口，镜像所有正式的 google api类型，即Key和PathElement，Entity和 EntityResult、QueryResultBatch和Value。这些类型将是 从任意数据存储操作返回，例如 Datastore.allocateIds(...)将返回Key实体的列表。
对于高级用法，所有这些数据类型都可能被重载。通用用例 可能是将实体反序列化为更具体的类。例如，给定 自定义实体类，如：
classMyEntityKind(gcloud.aio.datastore.Entity):def__init__(self,key,properties=None)->None:self.key=keyself.is_an_aardvark=(propertiesor{}).get('aardvark',False)def__repr__(self):return"I'm an aardvark!"ifself.is_an_aardvarkelse"Sorry, nope"
然后，我们可以将gcloud-aio-datastore配置为从 此自定义实体类具有：
classMyCustomDatastore(gcloud.aio.datastore.Datastore):entity_result_kind.entity_kind=MyEntityKind
可以用这种方式重写的类的完整列表是：
classMyVeryCustomDatastore(gcloud.aio.datastore.Datastore):datastore_operation_kind=DatastoreOperationentity_result_kind=EntityResultentity_result_kind.entity_kind=Entityentity_result_kind.entity_kind.key_kind=Keykey_kind=Keykey_kind.path_element_kind=PathElementquery_result_batch_kind=QueryResultBatchquery_result_batch_kind.entity_result_kind=EntityResultvalue_kind=Valuevalue_kind.key_kind=KeyclassMyVeryCustomQuery(gcloud.aio.datastore.Query):value_kind=ValueclassMyVeryCustomGQLQuery(gcloud.aio.datastore.GQLQuery):value_kind=Value
然后，您可以将MyVeryCustomDatastore类放在 以前使用过Datastore，对Query和GQLQuery执行同样的操作。
要重写任何子键，您需要重写使用它的任何父项。为了 例如，如果要使用自定义密钥类型并能够使用 它需要实现自己的Value、Query和GQLQuery 类并将它们连接到其他自定义类：
classMyKey(gcloud.aio.datastore.Key):passclassMyValue(gcloud.aio.datastore.Value):key_kind=MyKeyclassMyEntity(gcloud.aio.datastore.Entity):key_kind=MyKeyvalue_kind=MyValueclassMyEntityResult(gcloud.aio.datastore.EntityResult):entity_kind=MyEntityclassMyQueryResultBatch(gcloud.aio.datastore.QueryResultBatch):entity_result_kind=MyEntityResultclassMyDatastore(gcloud.aio.datastore.Datastore):key_kind=MyKeyentity_result_kind=MyEntityResultquery_result_batch=MyQueryResultBatchvalue_kind=MyValueclassMyQuery(gcloud.aio.datastore.Query):value_kind=MyValueclassMyGQLQuery(gcloud.aio.datastore.GQLQuery):value_kind=MyValue
贡献
请看我们的contributing guide。
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