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A Python module for creation, validation, and transformation of EPC representations as defined in GS1's EPC Tag Data Standard (https://www.gs1.org/standards/rfid/tds).

Table of contents

• EPCPY
  • Requirements
  • Installation
  • Scheme types
  • Available schemes
  • Generic parsers
  • Example usage
    • SGTIN
      • Pure identity
      • GS1Keyed
      • Tag encoded
    • Generic parsing
  • Exceptions
  • Development
    • Testing
    • Coverage
    • Notebook

• Python >= 3.8

pip install epcpy

Every scheme is an instance of theEPCScheme class, which allows scheme initialization using a constructor which accepts a EPC pure identity such asurn:epc:id:sgtin:00000950.01093.Serial or using the class methodfrom_epc_uri. Aside from this base class, schemes can also be instances of theGS1Keyed,GS1Element and/orTagEncodable classes. These provide the following methods:

EPCScheme

• constructor
• from_epc_uri

GS1Element / GS1Keyed

• from_gs1_element_string
• gs1_element_string
• gs1_key (ifGS1Keyed)

TagEncodable

• from_binary
• from_hex
• from_base64
• from_tag_uri
• binary
• hex
• base64
• tag_uri

An example highlighting the different options for theSGTIN scheme can be foundlater in this document .

The following generic parser functions are available

• base64_to_tag_encodable
• binary_to_tag_encodable
• hex_to_tag_encodable
• tag_uri_to_tag_encodable
• epc_pure_identity_to_gs1_element
• epc_pure_identity_to_gs1_element_string
• epc_pure_identity_to_gs1_key
• epc_pure_identity_to_gs1_keyed
• epc_pure_identity_to_scheme
• epc_pure_identity_to_tag_encodable
• get_gs1_key

Given anSGTIN in EPC URI representation,urn:epc:id:sgtin:00000950.01093.Serial, an epcpySGTIN object can be created as follows

fromepcpy.epc_schemesimportSGTINsgtin=SGTIN.from_epc_uri("urn:epc:id:sgtin:00000950.01093.Serial")# Alternativelysgtin=SGTIN("urn:epc:id:sgtin:00000950.01093.Serial")sgtin.epc_uri# urn:epc:id:sgtin:00000950.01093.Serial

SinceSGTIN isGS1Keyed, several elements can be derived using

sgtin.gs1_element_string()# (01)00000095010939(21)Serialsgtin.gs1_key()# 00000095010939fromepcpy.epc_schemes.sgtinimportGTIN_TYPEsgtin.gs1_key(gtin_type=GTIN_TYPE.GTIN8)# GTIN14 is the default# 95010939

Additionaly, anSGTIN can also be constructed from a GS1 element string if a company prefix length is provided

SGTIN.from_gs1_element_string("(01)00000095010939(21)Serial",company_prefix_length=8)

With some additional information anSGTIN can be encoded into a tag, subsequently the tag can for example be represented as tag uri, hexadecimal, base64 or binary string

sgtin.tag_uri(binary_coding_scheme=SGTIN.BinaryCodingScheme.SGTIN_198,filter_value=SGTINFilterValue.POS_ITEM)# urn:epc:tag:sgtin-198:1.00000950.01093.Serialsgtin.hex(binary_coding_scheme=SGTIN.BinaryCodingScheme.SGTIN_198,filter_value=SGTINFilterValue.POS_ITEM)# 36300001DB011169E5E5A70EC000000000000000000000000000sgtin.base64(binary_coding_scheme=SGTIN.BinaryCodingScheme.SGTIN_198,filter_value=SGTINFilterValue.POS_ITEM)# NjAAAdsBEWnl5acOwAAAAAAAAAAAAAAAAAAsgtin.binary(binary_coding_scheme=SGTIN.BinaryCodingScheme.SGTIN_198,filter_value=SGTINFilterValue.POS_ITEM)# 001101100011000000000000000000...

Similary, given aSGTIN tag in hex36300001DB011169E5E5A70EC000000000000000000000000000, anSGTIN can be constructed

SGTIN.from_hex("36300001DB011169E5E5A70EC000000000000000000000000000")# from_binary, from_base64 and from_tag_uri are available as well

When dealing with arbitrary tags epcpy also provides generic parsing options.

fromepcpyimporthex_to_epchex_to_epc("36300001DB011169E5E5A70EC000000000000000000000000000")

The following parsers are available:

• base64_to_tag_encodable
• binary_to_tag_encodable
• epc_pure_identity_to_gs1_element
• epc_pure_identity_to_gs1_element_string
• epc_pure_identity_to_gs1_key
• epc_pure_identity_to_gs1_keyed
• epc_pure_identity_to_scheme
• epc_pure_identity_to_tag_encodable
• hex_to_tag_encodable
• tag_uri_to_tag_encodable

Alternatively, theget_gs1_key method can be used to distill the GS1 key from a given string.

fromepcpyimportget_gs1_keyget_gs1_key("36300001DB011169E5E5A70EC000000000000000000000000000")# 00000095010939get_gs1_key("urn:epc:tag:sgtin-198:1.00000950.01093.Serial")# 00000095010939get_gs1_key("urn:epc:idpat:sgtin:00000950.01093.*")# 00000095010939

get_gs1_key is able to parse the following sources:

• EPC pure identity URIs
• EPC tag URIs
• GS1 element strings (company_prefix_length should be provided)
• EPC id pattern URIs
• Binary strings
• Hexadecimal strings

Especially when applying generic parsing, exceptions may be thrown when passing invalid data. One can import theConvertException class to specially deal with exceptions thrown by this library:

fromepcpyimportConvertException,get_gs1_keytry:get_gs1_key("urn:epc:idpat:sgtin:00000950.*.*")exceptConvertExceptionase:print(e)# Could not create valid scheme from given id pat

This project usesPoetry for project management.Poetry must be installed and available in$PATH.After cloning runpoetry install to install (development) dependencies.

This module uses the Python unittest library. Runpoetry run test for running the tests.

Runpoetry run coverage run -m unittest discover to execute all tests with coverage. The resulting coverage can be reported usingpoetry run coverage report --omit="*/test*" for a textual view the terminal and withpoetry run coverage html --omit="*/test*" for a webpage.

There is a sample notebook included in this repository, which can be used to quickly get a hands-on experience with the repository. The notebook might not be completely up-to-date and requires thejupyter package to run, which can be installed usingpip install jupyter.