DataObject - Object Storage Service - Alibaba Cloud Documentation Center

This topic describes the data type in OSS Connector for AI/ML.

Data type

Note

The DataObject data type in OSS Connector for AI/ML supports only the write-only or the read-only mode. The read-only mode supports sequential read and random read. The write-only mode supports only sequential write.

Example:

class DataObject:
    key: str
    size: int
    label: str

    def __enter__(self) -> DataObject: ...   
    def __exit__(self, exc_type, exc_val, exc_tb): ...
    def tell(self) -> int: ...
    def seek(self, offset: int, whence: int) -> int: ...
    def read(self, count: int) -> bytes: ...
    def readinto(self, buf) -> int: ...
    def write(self, data) -> int: ...
    def close(self) -> int: ...
    def copy(self) -> DataObject: ...

Methods

DataObject supports common I/O methods. The following table describes the I/O methods.

Method	Type/Return value type	Description
`key`	`str`	The unique identifier of the object.
`size`	`int`	The actual size of the object. Unit: bytes.
`label`	`str`	The tags of the object, which are used for classification or labeling.
`__enter__`	`DataObject`	The method that is used to go to the context manager to initialize the `DataObject` instance.
`__exit__`	`None`	The method that is used to exit the context manager to release resources or perform cleanup operations.
`tell`	`int`	Obtains the position of the current file pointer in read-only mode. Unit: bytes.
`seek`	`int`	Specifies the position of the file pointer in read-only mode. Unit: bytes.
`read`	`bytes`	Reads the specified number of bytes starting from the position of the current file pointer in read-only mode. Unit: `bytes`.
`readinto`	`int`	Reads data starting from the position of the current file pointer to the buffer in read-only mode, and returns the actual number of bytes that are read.
`write`	`int`	Writes data to the position of the current file pointer in write-only mode and returns the number of bytes that are written.
`close`	`int`	Closes the file and releases the related resources.
`copy`	`DataObject`	Creates a new `DataObject` instance that contains all attributes of the current instance.