GID

class epc.schemes.GID(*args, **kwargs)

The General Identifier EPC scheme is independent of any specifications or identity scheme outside the EPC global Tag Data Standard.

General syntax: urn:epc:id:gid:ManagerNumber.ObjectClass.SerialNumber

Example: urn:epc:id:gid:95100000.12345.400

Parameters

epc (str, optional) – Hexadecimal EPC tag data

manager_number(manager_number)

Set the manager number data for the tag.

The General Manager Number identifies an organizational entity (essentially a company, manager or other organization) that is responsible for maintaining the numbers in subsequent fields – Object Class and Serial Number.

GS1 assigns the General Manager Number to an entity, and ensures that each General Manager Number is unique. Note that a General Manager Number is not a GS1 Company Prefix. A General Manager Number may only be used in GID EPCs.

Parameters

manager_number (str, int) – GS1 manager number.

Raises

  • ValueError – Unable to convert string to an integer.

  • AttributeError – Input outside valid range (0 to 268435455).

Returns

The GID tag object.

Return type

epc.schemes.GID

object_class(object_class)

Set the object class data for the tag.

The Object Class is used by an EPC managing entity to identify a class or “type” of thing. These object class numbers, of course, must be unique within each General Manager Number domain.

Parameters

object_class (str, int) – Numeric object class.

Raises

  • ValueError – Unable to convert string to an integer.

  • AttributeError – Input outside valid range (0 to 16777215).

Returns

The GID tag object.

Return type

epc.schemes.GID

serial_number(serial_number)

Set the serial number data for the tag.

The Serial Number code, or serial number, is unique within each object class. In other words, the managing entity is responsible for assigning unique, non-repeating serial numbers for every instance within each object class.

Parameters

serial_number (str, int) – Numeric serial number.

Raises

  • ValueError – Unable to convert string to an integer.

  • AttributeError – Input outside valid range (0 to 68719476735).

Returns

The GID tag object.

Return type

epc.schemes.GID

property tag_uri
Returns

The tag’s URI.

Return type

str

property pure_identity_uri
Returns

The tag’s pure identity URI.

Return type

str

property values
Returns

Dictionary containing:

  • size (int): the tag’s size in bits

  • manager_number (int)

  • object_class (int)

  • serial_number (int)

decode_epc(hex_string)

Decode an encoded tag and populate this object’s values from it.

Parameters

hex_string (str) – Tag data encoded as a hexadecimal string.

Raises

  • ValueError – EPC scheme header does not match input.

  • ValueError – Supplied hex_string bit length invalid.

check_fields()

Checks to make sure all components of the tag are present, including size, manager_number, object_class and serial_number.

Raises

AttributeError – If any components of the tag are missing.

Hint

To get the encoded tag data, use python’s built in conversion methods:

>>> tag = GID()
>>> tag.manager_number(31231).object_class(11).serial_number(12)

# Hexadecimal
>>> hex(tag)
'0x3500079ff00000b00000000c'

# Binary
>>> bin(tag)
'0b1101010000000000000111100111111111000000000000000000001011000000000000000000000000000000001100'

Constants

GID.SIZE_96

96 bit tag size. Only size supported for this scheme.

GID.HEADER_96

GS1 specified hexadecimal header for 96 bit GID tags: 0x35.

GID.GID_96

Human readable GS1 specified header for 96 bit GID tags: gid-96.