DataObject methods and properties for OSS Connector for AI/ML - Object Storage Service

DataObject is a file-like object in OSS Connector for AI/ML that provides I/O access to OSS objects.

Note

DataObject supports only read-only or write-only mode—not both simultaneously. Read-only mode supports sequential read and random read. Write-only mode supports sequential write only.

Mode overview

Methods are mode-specific. The following table shows availability by mode:

Method	Read-only	Write-only
`tell`	Yes	—
`seek`	Yes	—
`read`	Yes	—
`readinto`	Yes	—
`write`	—	Yes
`close`	Yes	Yes

Class definition

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: ...

Properties

Property	Type	Description
`key`	`str`	The unique identifier of the object.
`size`	`int`	The actual size of the object, in bytes.
`label`	`str`	The tags associated with the object, used for classification or labeling.

Methods

Context manager methods

Method	Return type	Description
`__enter__`	`DataObject`	Enters the context manager and initializes the `DataObject` instance.
`__exit__`	`None`	Exits the context manager and releases resources.

Read-only methods

Method	Return type	Description
`tell`	`int`	Returns the current file pointer position in read-only mode, in bytes.
`seek(offset, whence)`	`int`	Specifies the file pointer position in read-only mode, in bytes.
`read(count)`	`bytes`	Reads the specified number of bytes from the current file pointer position in read-only mode.
`readinto(buf)`	`int`	Reads bytes from the current file pointer position into a buffer in read-only mode. Returns the number of bytes read.

Write-only methods

Method	Return type	Description
`write(data)`	`int`	Writes data to the current file pointer position in write-only mode. Returns the number of bytes written.

Common methods

Method	Return type	Description
`close`	`int`	Closes the object and releases related resources.
`copy`	`DataObject`	Creates a new `DataObject` instance with all attributes of the current instance.