pynetdicom.pdu_items.PresentationContextItemAC¶
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class
pynetdicom.pdu_items.
PresentationContextItemAC
¶ A Presentation Context (AC) Ttem.
Presentation Contexts (AC) Items are used by the association acceptor to signal which Abstract Syntaxes and Transfer Syntaxes have been accepted or rejected.
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item_length
¶ The number of bytes from the first byte following the Item Length field to the last byte of the Item.
Type: int
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item_type
¶ The Item Type field value (0x21).
Type: int
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presentation_context_id
¶ The Presentation Context ID field value, an odd integer between 1 and 255.
Type: int or None
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result_reason
¶ The Presentation Context’s Result/reason field value.
Type: int
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transfer_syntax
¶ The Presentation Context Item’s Transfer Syntax (if available).
Type: list of pydicom.uid.UID
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transfer_syntax_sub_item
¶ The Presentation Context Items’ Transfer Syntax Sub-item field value.
Type: list of pynetdicom.uid.UID
Notes
A Presentation Context (AC) Item requires the following parameters:
- Item type (1, fixed value, 0x21)
- Item length (1)
- Presentation context ID (1)
- Result/reason (1)
- Transfer Syntax Sub-item (1)
- Item type (1, fixed, 0x40)
- Item length (1)
- Transfer syntax name (1)
Encoding
When encoded, a Presentation Context (AC) Item has the following structure, taken from Table 9-13 [1] (offsets shown with Python indexing). Items are always encoded using Big Endian [2].
Offset Length Description 0 1 Item type 1 1 Reserved 2 2 Item length 4 1 Presentation context ID 5 1 Reserved 6 1 Result/reason 7 1 Reserved 8 Variable Transfer syntax sub-item References
[1] DICOM Standard, Part 8, Section 9.3.3.2 [2] DICOM Standard, Part 8, Section 9.3.1 -
__init__
()¶ Initialise a new Presentation Context (AC) Item.
Methods
__init__
()Initialise a new Presentation Context (AC) Item. decode
(bytestream)Decode bytestream and use the result to set the field values of the PDU item. encode
()Return the encoded PDU as bytes. from_primitive
(primitive)Set the item’s values using a Presentation Context primitive. to_primitive
()Return a PresentationContext primitive from the current Item. Attributes
context_id
Return the item’s Presentation Context ID field value. item_length
Return the item’s Item Length field value as an int. item_type
Return the item’s Item Type field value as an int. result
Return the item’s Result/reason field value. result_str
Get a string describing the result. transfer_syntax
Return the Transfer Syntax, if available. -
context_id
¶ Return the item’s Presentation Context ID field value.
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decode
(bytestream)¶ Decode bytestream and use the result to set the field values of the PDU item.
Parameters: bytestream (bytes) – The PDU data to be decoded.
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encode
()¶ Return the encoded PDU as bytes.
Returns: The encoded PDU. Return type: bytes
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from_primitive
(primitive)¶ Set the item’s values using a Presentation Context primitive.
Parameters: primitive (presentation.PresentationContext) – The primitive to use to set the Item’s field values.
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item_length
Return the item’s Item Length field value as an int.
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item_type
Return the item’s Item Type field value as an int.
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result
¶ Return the item’s Result/reason field value.
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result_str
¶ Get a string describing the result.
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to_primitive
()¶ Return a PresentationContext primitive from the current Item.
Returns: The primitive representation of the current Item. Return type: presentation.PresentationContext
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transfer_syntax
Return the Transfer Syntax, if available.
Returns: If no Transfer Syntax Sub-item or an empty Transfer Syntax Sub-item has been sent by the Acceptor then returns None, otherwise returns the Transfer Syntax Sub-item’s transfer syntax UID. Return type: pydicom.uid.UID or None
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