"""Validation classes for various types of data."""
import re
import typing
from abc import ABC, abstractmethod
from itertools import zip_longest
from operator import attrgetter
from marshmallow import types
from marshmallow.exceptions import ValidationError
_T = typing.TypeVar("_T")
[docs]class Validator(ABC):
"""Abstract base class for validators.
.. note::
This class does not provide any validation behavior. It is only used to
add a useful `__repr__` implementation for validators.
"""
error = None # type: typing.Optional[str]
def __repr__(self) -> str:
args = self._repr_args()
args = f"{args}, " if args else ""
return "<{self.__class__.__name__}({args}error={self.error!r})>".format(
self=self, args=args
)
def _repr_args(self) -> str:
"""A string representation of the args passed to this validator. Used by
`__repr__`.
"""
return ""
@abstractmethod
def __call__(self, value: typing.Any) -> typing.Any:
...
[docs]class And(Validator):
"""Compose multiple validators and combine their error messages.
Example: ::
from marshmallow import validate, ValidationError
def is_even(value):
if value % 2 != 0:
raise ValidationError("Not an even value.")
validator = validate.And(validate.Range(min=0), is_even)
validator(-1)
# ValidationError: ['Must be greater than or equal to 0.', 'Not an even value.']
:param validators: Validators to combine.
:param error: Error message to use when a validator returns ``False``.
"""
default_error_message = "Invalid value."
def __init__(
self, *validators: types.Validator, error: typing.Optional[str] = None
):
self.validators = tuple(validators)
self.error = error or self.default_error_message # type: str
def _repr_args(self) -> str:
return f"validators={self.validators!r}"
def __call__(self, value: typing.Any) -> typing.Any:
errors = []
kwargs = {}
for validator in self.validators:
try:
r = validator(value)
if not isinstance(validator, Validator) and r is False:
raise ValidationError(self.error)
except ValidationError as err:
kwargs.update(err.kwargs)
if isinstance(err.messages, dict):
errors.append(err.messages)
else:
# FIXME : Get rid of cast
errors.extend(typing.cast(list, err.messages))
if errors:
raise ValidationError(errors, **kwargs)
return value
[docs]class URL(Validator):
"""Validate a URL.
:param relative: Whether to allow relative URLs.
:param error: Error message to raise in case of a validation error.
Can be interpolated with `{input}`.
:param schemes: Valid schemes. By default, ``http``, ``https``,
``ftp``, and ``ftps`` are allowed.
:param require_tld: Whether to reject non-FQDN hostnames.
"""
class RegexMemoizer:
def __init__(self):
self._memoized = {}
def _regex_generator(self, relative: bool, require_tld: bool) -> typing.Pattern:
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: bool, require_tld: bool) -> typing.Pattern:
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 = {"http", "https", "ftp", "ftps"}
def __init__(
self,
*,
relative: bool = False,
schemes: typing.Optional[types.StrSequenceOrSet] = None,
require_tld: bool = True,
error: typing.Optional[str] = None,
):
self.relative = relative
self.error = error or self.default_message # type: str
self.schemes = schemes or self.default_schemes
self.require_tld = require_tld
def _repr_args(self) -> str:
return f"relative={self.relative!r}"
def _format_error(self, value) -> str:
return self.error.format(input=value)
def __call__(self, value: str) -> str:
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 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: typing.Optional[str] = None):
self.error = error or self.default_message # type: str
def _format_error(self, value: str) -> str:
return self.error.format(input=value)
def __call__(self, value: str) -> str:
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 passed to it is within the specified
range. 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. The inclusivity of the bounds (if they exist) is configurable.
If ``min_inclusive`` is not specified, or is specified as `True`, then
the ``min`` bound is included in the range. If ``max_inclusive`` is not specified,
or is specified as `True`, then the ``max`` bound is included in the range.
: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 min_inclusive: Whether the `min` bound is included in the range.
:param max_inclusive: Whether the `max` bound is included in the range.
:param error: Error message to raise in case of a validation error.
Can be interpolated with `{input}`, `{min}` and `{max}`.
"""
message_min = "Must be {min_op} {{min}}."
message_max = "Must be {max_op} {{max}}."
message_all = "Must be {min_op} {{min}} and {max_op} {{max}}."
message_gte = "greater than or equal to"
message_gt = "greater than"
message_lte = "less than or equal to"
message_lt = "less than"
def __init__(
self,
min=None,
max=None,
*,
min_inclusive: bool = True,
max_inclusive: bool = True,
error: typing.Optional[str] = None,
):
self.min = min
self.max = max
self.error = error
self.min_inclusive = min_inclusive
self.max_inclusive = max_inclusive
# interpolate messages based on bound inclusivity
self.message_min = self.message_min.format(
min_op=self.message_gte if self.min_inclusive else self.message_gt
)
self.message_max = self.message_max.format(
max_op=self.message_lte if self.max_inclusive else self.message_lt
)
self.message_all = self.message_all.format(
min_op=self.message_gte if self.min_inclusive else self.message_gt,
max_op=self.message_lte if self.max_inclusive else self.message_lt,
)
def _repr_args(self) -> str:
return "min={!r}, max={!r}, min_inclusive={!r}, max_inclusive={!r}".format(
self.min, self.max, self.min_inclusive, self.max_inclusive
)
def _format_error(self, value: _T, message: str) -> str:
return (self.error or message).format(input=value, min=self.min, max=self.max)
def __call__(self, value: _T) -> _T:
if self.min is not None and (
value < self.min if self.min_inclusive else 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 if self.max_inclusive else 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(Validator):
"""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 min: The minimum length. If not provided, minimum length
will not be checked.
:param max: The maximum length. If not provided, maximum length
will not be checked.
:param equal: The exact length. If provided, maximum and minimum
length will not be checked.
:param 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: typing.Optional[int] = None,
max: typing.Optional[int] = None,
*,
equal: typing.Optional[int] = None,
error: typing.Optional[str] = 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."
)
self.min = min
self.max = max
self.error = error
self.equal = equal
def _repr_args(self) -> str:
return f"min={self.min!r}, max={self.max!r}, equal={self.equal!r}"
def _format_error(self, value: typing.Sized, message: str) -> str:
return (self.error or message).format(
input=value, min=self.min, max=self.max, equal=self.equal
)
def __call__(self, value: typing.Sized) -> typing.Sized:
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 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: typing.Optional[str] = None):
self.comparable = comparable
self.error = error or self.default_message # type: str
def _repr_args(self) -> str:
return f"comparable={self.comparable!r}"
def _format_error(self, value: _T) -> str:
return self.error.format(input=value, other=self.comparable)
def __call__(self, value: _T) -> _T:
if value != self.comparable:
raise ValidationError(self._format_error(value))
return value
[docs]class Regexp(Validator):
"""Validator which succeeds if the ``value`` matches ``regex``.
.. note::
Uses `re.match`, which searches for a match at the beginning of a string.
: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 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: typing.Union[str, bytes, typing.Pattern],
flags: int = 0,
*,
error: typing.Optional[str] = None,
):
self.regex = (
re.compile(regex, flags) if isinstance(regex, (str, bytes)) else regex
)
self.error = error or self.default_message # type: str
def _repr_args(self) -> str:
return f"regex={self.regex!r}"
def _format_error(self, value: typing.Union[str, bytes]) -> str:
return self.error.format(input=value, regex=self.regex.pattern)
@typing.overload
def __call__(self, value: str) -> str:
...
@typing.overload
def __call__(self, value: bytes) -> bytes:
...
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 method: The name of the method to invoke.
:param 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: str, *, error: typing.Optional[str] = None, **kwargs):
self.method = method
self.error = error or self.default_message # type: str
self.kwargs = kwargs
def _repr_args(self) -> str:
return f"method={self.method!r}, kwargs={self.kwargs!r}"
def _format_error(self, value: typing.Any) -> str:
return self.error.format(input=value, method=self.method)
def __call__(self, value: typing.Any) -> typing.Any:
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: A sequence of invalid values.
:param 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: typing.Iterable, *, error: typing.Optional[str] = None
):
self.iterable = iterable
self.values_text = ", ".join(str(each) for each in self.iterable)
self.error = error or self.default_message # type: str
def _repr_args(self) -> str:
return f"iterable={self.iterable!r}"
def _format_error(self, value) -> str:
return self.error.format(input=value, values=self.values_text)
def __call__(self, value: typing.Any) -> typing.Any:
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 choices: A sequence of valid values.
:param labels: Optional sequence of labels to pair with the choices.
:param error: Error message to raise in case of a validation error. Can be
interpolated with `{input}`, `{choices}` and `{labels}`.
"""
default_message = "Must be one of: {choices}."
def __init__(
self,
choices: typing.Iterable,
labels: typing.Optional[typing.Iterable[str]] = None,
*,
error: typing.Optional[str] = None,
):
self.choices = choices
self.choices_text = ", ".join(str(choice) for choice in self.choices)
self.labels = labels if labels is not None else []
self.labels_text = ", ".join(str(label) for label in self.labels)
self.error = error or self.default_message # type: str
def _repr_args(self) -> str:
return f"choices={self.choices!r}, labels={self.labels!r}"
def _format_error(self, value) -> str:
return self.error.format(
input=value, choices=self.choices_text, labels=self.labels_text
)
def __call__(self, value: typing.Any) -> typing.Any:
try:
if value not in self.choices:
raise ValidationError(self._format_error(value))
except TypeError as error:
raise ValidationError(self._format_error(value)) from error
return value
[docs] def options(
self,
valuegetter: typing.Union[str, typing.Callable[[typing.Any], typing.Any]] = str,
) -> typing.Iterable[typing.Tuple[typing.Any, str]]:
"""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 `str()`.
"""
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``. Empty input
is considered valid.
:param iterable choices: Same as :class:`OneOf`.
:param iterable labels: Same as :class:`OneOf`.
:param str error: Same as :class:`OneOf`.
.. versionchanged:: 3.0.0b2
Duplicate values are considered valid.
.. versionchanged:: 3.0.0b2
Empty input is considered valid. Use `validate.Length(min=1) <marshmallow.validate.Length>`
to validate against empty inputs.
"""
default_message = "One or more of the choices you made was not in: {choices}."
def _format_error(self, value) -> str:
value_text = ", ".join(str(val) for val in value)
return super()._format_error(value_text)
def __call__(self, value: typing.Sequence[_T]) -> typing.Sequence[_T]:
# We can't use set.issubset because does not handle unhashable types
for val in value:
if val not in self.choices:
raise ValidationError(self._format_error(value))
return value
[docs]class ContainsNoneOf(NoneOf):
"""Validator which fails if ``value`` is a sequence and any element
in the sequence is a member of the sequence passed as ``iterable``. Empty input
is considered valid.
:param iterable iterable: Same as :class:`NoneOf`.
:param str error: Same as :class:`NoneOf`.
.. versionadded:: 3.6.0
"""
default_message = "One or more of the choices you made was in: {values}."
def _format_error(self, value) -> str:
value_text = ", ".join(str(val) for val in value)
return super()._format_error(value_text)
def __call__(self, value: typing.Sequence[_T]) -> typing.Sequence[_T]:
for val in value:
if val in self.iterable:
raise ValidationError(self._format_error(value))
return value
