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File-like Object

Native support for reading from object stores as a file-like object.

Use obstore.open or obstore.open_async to open files. Writing files in this way is not yet supported.

obstore.open 

open(store: ObjectStore, path: str) -> ReadableFile

Open a file object from the specified location.

Parameters:

  • store (ObjectStore) –

    The ObjectStore instance to use.

  • path (str) –

    The path within ObjectStore to retrieve.

Returns:

obstore.open_async async 

open_async(store: ObjectStore, path: str) -> AsyncReadableFile

Call open asynchronously, returning a file object with asynchronous operations.

Refer to the documentation for open.

obstore.ReadableFile

A readable file object with synchronous operations.

This implements a similar interface as a generic readable Python binary file-like object.

close 

close() -> None

Close the current file.

This is currently a no-op.

read 

read(size: int | None = None) -> Bytes

Read up to size bytes from the object and return them. As a convenience, if size is unspecified or None, all bytes until EOF are returned.

readall 

readall() -> Bytes

Read and return all the bytes from the stream until EOF, using multiple calls to the stream if necessary.

readline 

readline() -> Bytes

Read a single line of the file, up until the next newline character.

readlines 

readlines(hint: int = -1) -> List[Bytes]

Read all remaining lines into a list of buffers

seek 

seek(offset: int, whence: int = SEEK_SET) -> int

Change the stream position to the given byte offset, interpreted relative to the position indicated by whence, and return the new absolute position. Values for whence are:

  • os.SEEK_SET or 0: start of the stream (the default); offset should be zero or positive
  • os.SEEK_CUR or 1: current stream position; offset may be negative
  • os.SEEK_END or 2: end of the stream; offset is usually negative

seekable 

seekable() -> bool

Return True if the stream supports random access.

tell 

tell() -> int

Return the current stream position.

obstore.AsyncReadableFile

A readable file object with asynchronous operations.

close 

close() -> None

Close the current file.

This is currently a no-op.

read async 

read(size: int | None = None) -> Bytes

Read up to size bytes from the object and return them. As a convenience, if size is unspecified or None, all bytes until EOF are returned.

readall async 

readall() -> Bytes

Read and return all the bytes from the stream until EOF, using multiple calls to the stream if necessary.

readline async 

readline() -> Bytes

Read a single line of the file, up until the next newline character.

readlines async 

readlines(hint: int = -1) -> List[Bytes]

Read all remaining lines into a list of buffers

seek async 

seek(offset: int, whence: int = SEEK_SET) -> int

Change the stream position to the given byte offset, interpreted relative to the position indicated by whence, and return the new absolute position. Values for whence are:

  • os.SEEK_SET or 0: start of the stream (the default); offset should be zero or positive
  • os.SEEK_CUR or 1: current stream position; offset may be negative
  • os.SEEK_END or 2: end of the stream; offset is usually negative

seekable 

seekable() -> bool

Return True if the stream supports random access.

tell async 

tell() -> int

Return the current stream position.