ISBN

Canonicalizes one ISBN identifier per call with check-digit validation, converting legacy ISBN-10 to ISBN-13 when enabled.

In plain language: give it "9780306406157" or "0306406152" and it hands back the 13-digit ISBN if the check digit is correct. The hyphenated form is a presentation option — the underlying value is always the bare digits unless you ask for hyphens.

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What it recognizes — and what it does not

Recognizes	Does not recognize
ISBN-13 bare digits with 978 or 979 prefix (9780306406157)	ISBNs with wrong check digits — recognized but INVALID
ISBN-10 (0306406152) — only when include_isbn10=True (the default)	ISBN-10 when include_isbn10=False → MISSING
Hyphenated input is normalized regardless of input hyphens — output hyphens are via output_format	Informal variants or partial numbers — MISSING

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Canonical output

Default output_format is "isbn13" (bare 13 digits).

output_format	Renders	Example for 9780110002224
(default) isbn13 / None / "default"	bare 13 digits	9780110002224
hyphenated	hyphenated by registrant-range (ISBN Range Message, longest-match)	978-0-11-000222-4

Hyphenation is presentation only — provenance remains the same; the hyphen positions come from the authoritative Range Message table.

from paxman.capabilities import ISBN
import paxman

paxman.register_all_shipped()
paxman.canonicalize(
    "9780110002224", ISBN.create_contract()
).canonicalized_value  # "9780110002224"
paxman.canonicalize(
    "9780110002224", ISBN.create_contract(output_format="hyphenated")
).canonicalized_value  # "978-0-11-000222-4"
paxman.canonicalize(
    "0306406152", ISBN.create_contract()
).canonicalized_value  # "9780306406157" (10 → 13)

---

Contract

contract = ISBN.create_contract(
    include_isbn10=True,  # bool, default True  — recognize ISBN-10
    include_range_validation=False,  # bool, default False — gate the registrant-range rule/provenance
    output_format=None,  # "isbn13" (default) or "hyphenated"
    # plus every common field: excluded_rules / pinned_rules / year / extra_grammars
)

• With include_isbn10=False, only the isbn13_recognition grammar runs — ISBN-10 input is MISSING (never seen), not INVALID.
• output_format="hyphenated" controls hyphenation (uses the Range Message longest-match table) and works regardless of include_range_validation. include_range_validation=True separately enables the Range Message registrant-range rule that adds provenance — it does not change the canonical digits, and hyphenation does not by itself add that provenance.

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Statuses

Input	Contract	Status	Why
9780306406157	defaults	SUCCESS	bare ISBN-13, check digit valid
0306406152	defaults	SUCCESS	ISBN-10 → 9780306406157
0306406152	include_isbn10=False	MISSING	grammar not active
9780306406150 (bad check)	any	INVALID	recognized but check digit fails
hello	any	MISSING	no ISBN pattern
Two distinct ISBNs in one call	any	raises MultipleMentionsError	split first

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Notebook snippet

import paxman
from paxman.capabilities import ISBN
from paxman.core.domain import Resolution

paxman.register_all_shipped()
c = ISBN.create_contract()
c_hyph = ISBN.create_contract(output_format="hyphenated")

for text in ["9780306406157", "0306406152", "9780306406150", "hello"]:
    r = paxman.canonicalize(text, c)
    rh = paxman.canonicalize(text, c_hyph)
    a = r.canonicalized_value or "—"
    b = rh.canonicalized_value or "—"
    print(f"{text!r:20} → bare {a!r:15} hyphenated {b!r:20} status={r.status.value}")

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Provenance

• ISO 2108 — GS1 / ISBN prefix.
• ISBN Users’ Manual — ISBN-13 / ISBN-10 check-digit logic.
• ISBN Range Message — registrant-range hyphenation and provenance (only with include_range_validation=True).

See also: Execution Result, Provenance, Segmentation.