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Top-level domain names are rejected erroneously by both hostname() and domain() #442
Closed as not planned
Description
Syntactically valid, top-level domain names, with and without the final (RFC1034) dot,
are rejected by validators.domain().
Syntactically valid, top-level domain names, but only with the final (RFC1034) dot,
are rejected by validators.hostname().
In each case, this is incorrect.
Details are shown in the test run recorded below.
$ python
Python 3.13.1 (heads/ech:01878d639d, Dec 7 2025, 16:31:00) [GCC 13.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> from validators import __version__ as version
>>> from validators import domain as is_domain
>>> from validators import hostname as is_hostname
>>> from pprint import pprint
>>>
>>> version
'0.35.0'
>>>
>>> samples = [ 'yu.', 'yu', 'yugoslavia.yu.', 'yugoslavia.yu', 'ie.', 'ie', 'defo.ie.', 'defo.ie' ]
>>>
>>> pprint(list(map(lambda x: (x, is_domain(x, rfc_1034=True)), samples)))
[('yu.', ValidationError(func=domain, args={'value': 'yu.', 'rfc_1034': True})),
('yu', ValidationError(func=domain, args={'value': 'yu', 'rfc_1034': True})),
('yugoslavia.yu.', True),
('yugoslavia.yu', True),
('ie.', ValidationError(func=domain, args={'value': 'ie.', 'rfc_1034': True})),
('ie', ValidationError(func=domain, args={'value': 'ie', 'rfc_1034': True})),
('defo.ie.', True),
('defo.ie', True)]
>>>
>>> pprint(list(map(lambda x: (x, is_hostname(x, rfc_1034=True, maybe_simple=True)), samples)))
[('yu.',
ValidationError(func=hostname, args={'value': 'yu.', 'rfc_1034': True, 'maybe_simple': True})),
('yu', True),
('yugoslavia.yu.', True),
('yugoslavia.yu', True),
('ie.',
ValidationError(func=hostname, args={'value': 'ie.', 'rfc_1034': True, 'maybe_simple': True})),
('ie', True),
('defo.ie.', True),
('defo.ie', True)]
>>>
Activity
Accept trailing dot on simple hostnames with rfc_1034
nandgator commentedon Oct 10, 2026
Partly fixed:
hostname('yu.', rfc_1034=True)(a single label with the RFC 1034 trailing dot) is now accepted (#462). What remains isdomain('yu')/domain('ie.'):domain()requires a dotted name with a TLD by design, whereas a bare single label is covered byhostname(..., maybe_simple=True). Leaving this open for a maintainer decision on whetherdomain()should accept single labels.nandgator commentedon Oct 10, 2026
Decision:
domain()keeps requiring a dotted name with a TLD, sodomain('yu')anddomain('ie.')stay invalid by design. The hostname half of this report is fixed (#462):hostname('yu.', rfc_1034=True)is accepted, and single-label names are validated withhostname(..., maybe_simple=True). Thanks for the detailed report!