Add hostname validator

tests/test_hostname.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+import pytest
+
+from validators import hostname, ValidationFailure
+
+
+@pytest.mark.parametrize(('address',), [
+    ('127.0.0.1',),
+    ('123.5.77.88',),
+    ('12.12.12.12',),
+    ('google.com',),
+    ('www.duck.com',),
+    ('ashdjkha.asdjaks.to',),
+])
+def test_returns_true_on_valid_hostname(address):
+    assert hostname(address)
+
+
+@pytest.mark.parametrize(('address',), [
+    ('abc.0.0.1',),
+    ('1278.0.0.1',),
+    ('900.200.100.75',),
+    ('0127.0.0.1',),
+    ('!@#google.com',),
+    ('  www.duck.com',),
+    ('ashdj_>kha.asdjaks.to',),
+])
+def test_returns_failed_validation_on_invalid_hostname(address):
+    assert isinstance(hostname(address), ValidationFailure)

validators/__init__.py

@@ -14,6 +14,7 @@
 from .email import email
 from .extremes import Max, Min
 from .hashes import md5, sha1, sha224, sha256, sha512
+from .hostname import hostname
 from .i18n import fi_business_id, fi_ssn
 from .iban import iban
 from .ip_address import ipv4, ipv4_cidr, ipv6, ipv6_cidr
@@ -26,7 +27,7 @@
 from .uuid import uuid
 
 __all__ = ('between', 'domain', 'email', 'Max', 'Min', 'md5', 'sha1', 'sha224',
-           'sha256', 'sha512', 'fi_business_id', 'fi_ssn', 'iban', 'ipv4',
+           'sha256', 'sha512', 'fi_business_id', 'fi_ssn', 'hostname', 'iban', 'ipv4',
            'ipv4_cidr', 'ipv6', 'ipv6_cidr', 'length', 'mac_address', 'slug',
            'truthy', 'url', 'ValidationFailure', 'validator', 'uuid',
            'card_number', 'visa', 'mastercard', 'amex', 'unionpay', 'diners',

validators/hostname.py

@@ -0,0 +1,38 @@
+import re
+
+from .utils import validator
+
+"""
+sources:
+https://regexr.com/3dt4r
+"""
+hostname_re = re.compile(
+    r"^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$|^(([a-zA-Z0-9]|["
+    r"a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)+([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])$",
+    re.IGNORECASE)
+
+
+def to_unicode(obj, charset='utf-8', errors='strict'):
+    if obj is None:
+        return None
+    if not isinstance(obj, bytes):
+        return str(obj)
+    return obj.decode(charset, errors)
+
+
+@validator
+def hostname(value: str):
+    """
+    Return whether a given value is a valid hostname.
+    If the value is valid hostname this function returns ``True``, otherwise
+    :class:`~validators.utils.ValidationFailure`.
+    Examples::
+        >>>
+        True
+    :param value: hostname string to validate
+    to the end if the procided value and validation retried)
+    """
+    try:
+        return hostname_re.match(to_unicode(value).encode('idna').decode('ascii'))
+    except (UnicodeError, AttributeError):
+        return False