pydicom.filebase.DicomIO

class pydicom.filebase.DicomIO(buffer: ReadableBuffer | WriteableBuffer)

Wrapper for managing buffer-like objects used when reading or writing DICOM datasets.

__init__(buffer: ReadableBuffer | WriteableBuffer) → None

Create a new DicomIO instance.

Parameters:

buffer (buffer-like object) –

A buffer-like object that implements:

• seek() and tell() methods with the same signatures as io.IOBase.seek() and io.IOBase.tell()

• a read() method with the same signature as io.RawIOBase.read() if it supports reading data from itself, and/or

• a write() method with the same signature as io.RawIOBase.write() if it supports writing data to itself

If buffer supports reading it can be used with dcmread() as the source to decode a DICOM dataset from, and if it supports writing it can be used with dcmwrite() as the destination for the encoded DICOM dataset.

Methods

__init__(buffer)	Create a new DicomIO instance.
close(*args, **kwargs)	Close the buffer (if possible)
read([size])	Read up to size bytes from the buffer and return them.
read_UL()	Return a UL value read from the buffer.
read_US()	Return a US value read from the buffer.
read_exact(length[, nr_retries])	Return length bytes read from the buffer.
read_tag()	Return a DICOM tag value read from the buffer.
seek(offset[, whence])	Change the buffer position to the given byte offset, relative to the position indicated by whence and return the new absolute position.
tell()	Return the current stream position of the buffer
write(b, /)	Write the bytes-like object b to the buffer and return the number of bytes written.
write_UL(val)	Write a UL value to the buffer.
write_US(val)	Write a US value to the buffer.
write_tag(tag)	Write a DICOM tag to the buffer.

Attributes

is_implicit_VR	Get/set the VR mode for encoding/decoding.
is_little_endian	Get/set the endianness for encoding/decoding, True for little endian and False for big endian.
name	Return the value of the parent's name attribute, or None if no such attribute.
parent	Return the buffer object being wrapped.

close(*args: Any, **kwargs: Any) → Any

Close the buffer (if possible)

property is_implicit_VR: bool

Get/set the VR mode for encoding/decoding. True for implicit VR and False for explicit VR.

property is_little_endian: bool

Get/set the endianness for encoding/decoding, True for little endian and False for big endian.

property name: str | None

Return the value of the parent’s name attribute, or None if no such attribute.

property parent: ReadableBuffer | WriteableBuffer

Return the buffer object being wrapped.

read(size: int = -1, /) → bytes

Read up to size bytes from the buffer and return them. If size is unspecified, all bytes until EOF are returned.

Fewer than size bytes may be returned if the operating system call returns fewer than size bytes.

read_UL() → int

Return a UL value read from the buffer.

read_US() → int

Return a US value read from the buffer.

read_exact(length: int, nr_retries: int = 3) → bytes

Return length bytes read from the buffer.

Parameters:

• length (int) – The number of bytes to be read. If None (default) then read all the bytes available.

• nr_retries (int, optional) – The number of tries to read data when the number of bytes read from the buffer is less than length. Default 3.

Returns:

The read data.

Return type:

bytes

Raises:

EOFError – If unable to read length bytes.

read_tag() → tuple[int, int]

Return a DICOM tag value read from the buffer.

seek(offset: int, whence: int = 0, /) → int

Change the buffer position to the given byte offset, relative to the position indicated by whence and return the new absolute position.

tell() → int

Return the current stream position of the buffer

write(b: bytes | bytearray | memoryview, /) → int

Write the bytes-like object b to the buffer and return the number of bytes written.

write_UL(val: int) → None

Write a UL value to the buffer.

write_US(val: int) → None

Write a US value to the buffer.

write_tag(tag: int) → None

Write a DICOM tag to the buffer.