# -*- coding: utf-8 -*-
"""Validation classes for various types of data."""
from __future__ import unicode_literals
import re
from operator import attrgetter
from marshmallow.compat import basestring, text_type, zip_longest
from marshmallow.exceptions import ValidationError
[docs]class Validator(object):
"""Base abstract class for validators.
.. note::
This class does not provide any behavior. It is only used to
add a useful `__repr__` implementation for validators.
"""
def __repr__(self):
args = self._repr_args()
args = '{0}, '.format(args) if args else ''
return (
'<{self.__class__.__name__}({args}error={self.error!r})>'
.format(self=self, args=args)
)
def _repr_args(self):
"""A string representation of the args passed to this validator. Used by
`__repr__`.
"""
return ''
[docs]class URL(Validator):
"""Validate a URL.
:param bool relative: Whether to allow relative URLs.
:param str error: Error message to raise in case of a validation error.
Can be interpolated with `{input}`.
:param set schemes: Valid schemes. By default, ``http``, ``https``,
``ftp``, and ``ftps`` are allowed.
:param bool require_tld: Whether to reject non-FQDN hostnames
"""
class RegexMemoizer(object):
def __init__(self):
self._memoized = {}
def _regex_generator(self, relative, require_tld):
return re.compile(r''.join((
r'^',
r'(' if relative else r'',
r'(?:[a-z0-9\.\-\+]*)://', # scheme is validated separately
r'(?:[^:@]+?(:[^:@]*?)?@|)', # basic auth
r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+',
r'(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|', # domain...
r'localhost|', # localhost...
(r'(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.?)|'
if not require_tld else r''), # allow dotless hostnames
r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}|', # ...or ipv4
r'\[?[A-F0-9]*:[A-F0-9:]+\]?)', # ...or ipv6
r'(?::\d+)?', # optional port
r')?' if relative else r'', # host is optional, allow for relative URLs
r'(?:/?|[/?]\S+)\Z',
)), re.IGNORECASE)
def __call__(self, relative, require_tld):
key = (relative, require_tld)
if key not in self._memoized:
self._memoized[key] = self._regex_generator(relative, require_tld)
return self._memoized[key]
_regex = RegexMemoizer()
default_message = 'Not a valid URL.'
default_schemes = set(['http', 'https', 'ftp', 'ftps'])
# TODO; Switch position of `error` and `schemes` in 3.0
def __init__(self, relative=False, error=None, schemes=None, require_tld=True):
self.relative = relative
self.error = error or self.default_message
self.schemes = schemes or self.default_schemes
self.require_tld = require_tld
def _repr_args(self):
return 'relative={0!r}'.format(self.relative)
def _format_error(self, value):
return self.error.format(input=value)
def __call__(self, value):
message = self._format_error(value)
if not value:
raise ValidationError(message)
# Check first if the scheme is valid
if '://' in value:
scheme = value.split('://')[0].lower()
if scheme not in self.schemes:
raise ValidationError(message)
regex = self._regex(self.relative, self.require_tld)
if not regex.search(value):
raise ValidationError(message)
return value
[docs]class Email(Validator):
"""Validate an email address.
:param str error: Error message to raise in case of a validation error. Can be
interpolated with `{input}`.
"""
USER_REGEX = re.compile(
r"(^[-!#$%&'*+/=?^`{}|~\w]+(\.[-!#$%&'*+/=?^`{}|~\w]+)*\Z" # dot-atom
# quoted-string
r'|^"([\001-\010\013\014\016-\037!#-\[\]-\177]'
r'|\\[\001-\011\013\014\016-\177])*"\Z)', re.IGNORECASE | re.UNICODE)
DOMAIN_REGEX = re.compile(
# domain
r'(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+'
r'(?:[A-Z]{2,6}|[A-Z0-9-]{2,})\Z'
# literal form, ipv4 address (SMTP 4.1.3)
r'|^\[(25[0-5]|2[0-4]\d|[0-1]?\d?\d)'
r'(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\]\Z', re.IGNORECASE | re.UNICODE)
DOMAIN_WHITELIST = ('localhost',)
default_message = 'Not a valid email address.'
def __init__(self, error=None):
self.error = error or self.default_message
def _format_error(self, value):
return self.error.format(input=value)
def __call__(self, value):
message = self._format_error(value)
if not value or '@' not in value:
raise ValidationError(message)
user_part, domain_part = value.rsplit('@', 1)
if not self.USER_REGEX.match(user_part):
raise ValidationError(message)
if domain_part not in self.DOMAIN_WHITELIST:
if not self.DOMAIN_REGEX.match(domain_part):
try:
domain_part = domain_part.encode('idna').decode('ascii')
except UnicodeError:
pass
else:
if self.DOMAIN_REGEX.match(domain_part):
return value
raise ValidationError(message)
return value
[docs]class Range(Validator):
"""Validator which succeeds if the value it is passed is greater
or equal to ``min`` and less than or equal to ``max``. If ``min``
is not specified, or is specified as `None`, no lower bound
exists. If ``max`` is not specified, or is specified as `None`,
no upper bound exists.
:param min: The minimum value (lower bound). If not provided, minimum
value will not be checked.
:param max: The maximum value (upper bound). If not provided, maximum
value will not be checked.
:param str error: Error message to raise in case of a validation error.
Can be interpolated with `{input}`, `{min}` and `{max}`.
"""
message_min = 'Must be at least {min}.'
message_max = 'Must be at most {max}.'
message_all = 'Must be between {min} and {max}.'
def __init__(self, min=None, max=None, error=None):
self.min = min
self.max = max
self.error = error
def _repr_args(self):
return 'min={0!r}, max={1!r}'.format(self.min, self.max)
def _format_error(self, value, message):
return (self.error or message).format(input=value, min=self.min, max=self.max)
def __call__(self, value):
if self.min is not None and value < self.min:
message = self.message_min if self.max is None else self.message_all
raise ValidationError(self._format_error(value, message))
if self.max is not None and value > self.max:
message = self.message_max if self.min is None else self.message_all
raise ValidationError(self._format_error(value, message))
return value
[docs]class Length(Range):
"""Validator which succeeds if the value passed to it has a
length between a minimum and maximum. Uses len(), so it
can work for strings, lists, or anything with length.
:param int min: The minimum length. If not provided, minimum length
will not be checked.
:param int max: The maximum length. If not provided, maximum length
will not be checked.
:param int equal: The exact length. If provided, maximum and minimum
length will not be checked.
:param str error: Error message to raise in case of a validation error.
Can be interpolated with `{input}`, `{min}` and `{max}`.
"""
message_min = 'Shorter than minimum length {min}.'
message_max = 'Longer than maximum length {max}.'
message_all = 'Length must be between {min} and {max}.'
message_equal = 'Length must be {equal}.'
def __init__(self, min=None, max=None, error=None, equal=None):
if equal is not None and any([min, max]):
raise ValueError(
'The `equal` parameter was provided, maximum or '
'minimum parameter must not be provided.'
)
super(Length, self).__init__(min, max, error)
self.equal = equal
def _repr_args(self):
return 'min={0!r}, max={1!r}, equal={2!r}'.format(self.min, self.max, self.equal)
def _format_error(self, value, message):
return (self.error or message).format(input=value, min=self.min, max=self.max,
equal=self.equal)
def __call__(self, value):
length = len(value)
if self.equal is not None:
if length != self.equal:
raise ValidationError(self._format_error(value, self.message_equal))
return value
if self.min is not None and length < self.min:
message = self.message_min if self.max is None else self.message_all
raise ValidationError(self._format_error(value, message))
if self.max is not None and length > self.max:
message = self.message_max if self.min is None else self.message_all
raise ValidationError(self._format_error(value, message))
return value
[docs]class Equal(Validator):
"""Validator which succeeds if the ``value`` passed to it is
equal to ``comparable``.
:param comparable: The object to compare to.
:param str error: Error message to raise in case of a validation error.
Can be interpolated with `{input}` and `{other}`.
"""
default_message = 'Must be equal to {other}.'
def __init__(self, comparable, error=None):
self.comparable = comparable
self.error = error or self.default_message
def _repr_args(self):
return 'comparable={0!r}'.format(self.comparable)
def _format_error(self, value):
return self.error.format(input=value, other=self.comparable)
def __call__(self, value):
if value != self.comparable:
raise ValidationError(self._format_error(value))
return value
[docs]class Regexp(Validator):
"""Validate ``value`` against the provided regex.
:param regex: The regular expression string to use. Can also be a compiled
regular expression pattern.
:param flags: The regexp flags to use, for example re.IGNORECASE. Ignored
if ``regex`` is not a string.
:param str error: Error message to raise in case of a validation error.
Can be interpolated with `{input}` and `{regex}`.
"""
default_message = 'String does not match expected pattern.'
def __init__(self, regex, flags=0, error=None):
self.regex = re.compile(regex, flags) if isinstance(regex, basestring) else regex
self.error = error or self.default_message
def _repr_args(self):
return 'regex={0!r}'.format(self.regex)
def _format_error(self, value):
return self.error.format(input=value, regex=self.regex.pattern)
def __call__(self, value):
if self.regex.match(value) is None:
raise ValidationError(self._format_error(value))
return value
[docs]class Predicate(Validator):
"""Call the specified ``method`` of the ``value`` object. The
validator succeeds if the invoked method returns an object that
evaluates to True in a Boolean context. Any additional keyword
argument will be passed to the method.
:param str method: The name of the method to invoke.
:param str error: Error message to raise in case of a validation error.
Can be interpolated with `{input}` and `{method}`.
:param kwargs: Additional keyword arguments to pass to the method.
"""
default_message = 'Invalid input.'
def __init__(self, method, error=None, **kwargs):
self.method = method
self.error = error or self.default_message
self.kwargs = kwargs
def _repr_args(self):
return 'method={0!r}, kwargs={1!r}'.format(self.method, self.kwargs)
def _format_error(self, value):
return self.error.format(input=value, method=self.method)
def __call__(self, value):
method = getattr(value, self.method)
if not method(**self.kwargs):
raise ValidationError(self._format_error(value))
return value
[docs]class NoneOf(Validator):
"""Validator which fails if ``value`` is a member of ``iterable``.
:param iterable iterable: A sequence of invalid values.
:param str error: Error message to raise in case of a validation error. Can be
interpolated using `{input}` and `{values}`.
"""
default_message = 'Invalid input.'
def __init__(self, iterable, error=None):
self.iterable = iterable
self.values_text = ', '.join(text_type(each) for each in self.iterable)
self.error = error or self.default_message
def _repr_args(self):
return 'iterable={0!r}'.format(self.iterable)
def _format_error(self, value):
return self.error.format(
input=value,
values=self.values_text,
)
def __call__(self, value):
try:
if value in self.iterable:
raise ValidationError(self._format_error(value))
except TypeError:
pass
return value
[docs]class OneOf(Validator):
"""Validator which succeeds if ``value`` is a member of ``choices``.
:param iterable choices: A sequence of valid values.
:param iterable labels: Optional sequence of labels to pair with the choices.
:param str error: Error message to raise in case of a validation error. Can be
interpolated with `{input}`, `{choices}` and `{labels}`.
"""
default_message = 'Not a valid choice.'
def __init__(self, choices, labels=None, error=None):
self.choices = choices
self.choices_text = ', '.join(text_type(choice) for choice in self.choices)
self.labels = labels if labels is not None else []
self.labels_text = ', '.join(text_type(label) for label in self.labels)
self.error = error or self.default_message
def _repr_args(self):
return 'choices={0!r}, labels={1!r}'.format(self.choices, self.labels)
def _format_error(self, value):
return self.error.format(
input=value,
choices=self.choices_text,
labels=self.labels_text,
)
def __call__(self, value):
try:
if value not in self.choices:
raise ValidationError(self._format_error(value))
except TypeError:
raise ValidationError(self._format_error(value))
return value
[docs] def options(self, valuegetter=text_type):
"""Return a generator over the (value, label) pairs, where value
is a string associated with each choice. This convenience method
is useful to populate, for instance, a form select field.
:param valuegetter: Can be a callable or a string. In the former case, it must
be a one-argument callable which returns the value of a
choice. In the latter case, the string specifies the name
of an attribute of the choice objects. Defaults to `str()`
or `unicode()`.
"""
valuegetter = valuegetter if callable(valuegetter) else attrgetter(valuegetter)
pairs = zip_longest(self.choices, self.labels, fillvalue='')
return ((valuegetter(choice), label) for choice, label in pairs)
[docs]class ContainsOnly(OneOf):
"""Validator which succeeds if ``value`` is a sequence and each element
in the sequence is also in the sequence passed as ``choices``.
:param iterable choices: Same as :class:`OneOf`.
:param iterable labels: Same as :class:`OneOf`.
:param str error: Same as :class:`OneOf`.
"""
default_message = 'One or more of the choices you made was not acceptable.'
def _format_error(self, value):
value_text = ', '.join(text_type(val) for val in value)
return super(ContainsOnly, self)._format_error(value_text)
def __call__(self, value):
choices = list(self.choices)
if not value and choices:
raise ValidationError(self._format_error(value))
# We check list.index instead of using set.issubset so that
# unhashable types are handled.
for val in value:
try:
index = choices.index(val)
except ValueError:
raise ValidationError(self._format_error(value))
else:
del choices[index]
return value
