Checksum Validator

• ean_validate — Validates an 8-digit (EAN-8), 12-digit (UPC-A), 13-digit (EAN-13), or 14-digit (GTIN-14) barcode checksum: alternating weights 1 3 applied right-to-left, check
• iban_validate — Validates an IBAN's length for its issuing country (per the SWIFT IBAN registry) and its mod-97 checksum. Does not decompose the BBAN into a bank code/account n
• isbn_validate — Validates a 10- or 13-character ISBN. ISBN-10 uses weights 10..1 over 10 characters (last may be X, worth 10), sum mod 11 must be 0. ISBN-13 uses the same GTIN
• luhn_validate — Validates a numeric string against the Luhn (mod-10) checksum — payment card numbers, IMEI numbers, and similar identifiers.
• swiftbic_validate — Structural format validation only for a SWIFT/BIC code: 8 or 11 characters (4 letters bank code + 2 letters country code + 2 alphanumeric location code + option
• vateu_validate — Format validation only (no VIES lookup) for an EU VAT number: checks the 2-letter member-state prefix (EL for Greece, XI for Northern Ireland) against that coun

No long description beyond the summary.