biip.gs1.checksums

Checksum algorithms used by GS1 standards.

biip.gs1.checksums.numeric_check_digit(value)

Get GS1 check digit for numeric string.

Parameters

value (str) – The numeric string to calculate the check digit for.

Return type

int

Returns

The check digit.

Raises

ValueError – If the value isn’t numeric.

References

GS1 General Specification, section 7.9

Example

>>> from biip.gs1.checksums import numeric_check_digit
>>> numeric_check_digit("950110153100")  # GTIN-13
0
>>> numeric_check_digit("9501234")  # GTIN-8
6
biip.gs1.checksums.price_check_digit(value)

Get GS1 check digit for a price or weight field.

Parameters

value (str) – The numeric string to calculate the check digit for.

Return type

int

Returns

The check digit.

Raises

ValueError – If the value isn’t numeric.

References

GS1 General Specification, section 7.9.2-7.9.4

Example

>>> from biip.gs1.checksums import price_check_digit
>>> price_check_digit("2875")
9
>>> price_check_digit("14685")
6