|
|
|
|
|
""" |
|
Commonly useful validators. |
|
""" |
|
|
|
|
|
import operator |
|
import re |
|
|
|
from contextlib import contextmanager |
|
from re import Pattern |
|
|
|
from ._config import get_run_validators, set_run_validators |
|
from ._make import _AndValidator, and_, attrib, attrs |
|
from .converters import default_if_none |
|
from .exceptions import NotCallableError |
|
|
|
|
|
__all__ = [ |
|
"and_", |
|
"deep_iterable", |
|
"deep_mapping", |
|
"disabled", |
|
"ge", |
|
"get_disabled", |
|
"gt", |
|
"in_", |
|
"instance_of", |
|
"is_callable", |
|
"le", |
|
"lt", |
|
"matches_re", |
|
"max_len", |
|
"min_len", |
|
"not_", |
|
"optional", |
|
"provides", |
|
"set_disabled", |
|
] |
|
|
|
|
|
def set_disabled(disabled): |
|
""" |
|
Globally disable or enable running validators. |
|
|
|
By default, they are run. |
|
|
|
:param disabled: If ``True``, disable running all validators. |
|
:type disabled: bool |
|
|
|
.. warning:: |
|
|
|
This function is not thread-safe! |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
set_run_validators(not disabled) |
|
|
|
|
|
def get_disabled(): |
|
""" |
|
Return a bool indicating whether validators are currently disabled or not. |
|
|
|
:return: ``True`` if validators are currently disabled. |
|
:rtype: bool |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
return not get_run_validators() |
|
|
|
|
|
@contextmanager |
|
def disabled(): |
|
""" |
|
Context manager that disables running validators within its context. |
|
|
|
.. warning:: |
|
|
|
This context manager is not thread-safe! |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
set_run_validators(False) |
|
try: |
|
yield |
|
finally: |
|
set_run_validators(True) |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _InstanceOfValidator: |
|
type = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if not isinstance(value, self.type): |
|
msg = "'{name}' must be {type!r} (got {value!r} that is a {actual!r}).".format( |
|
name=attr.name, |
|
type=self.type, |
|
actual=value.__class__, |
|
value=value, |
|
) |
|
raise TypeError( |
|
msg, |
|
attr, |
|
self.type, |
|
value, |
|
) |
|
|
|
def __repr__(self): |
|
return f"<instance_of validator for type {self.type!r}>" |
|
|
|
|
|
def instance_of(type): |
|
""" |
|
A validator that raises a `TypeError` if the initializer is called |
|
with a wrong type for this particular attribute (checks are performed using |
|
`isinstance` therefore it's also valid to pass a tuple of types). |
|
|
|
:param type: The type to check for. |
|
:type type: type or tuple of type |
|
|
|
:raises TypeError: With a human readable error message, the attribute |
|
(of type `attrs.Attribute`), the expected type, and the value it |
|
got. |
|
""" |
|
return _InstanceOfValidator(type) |
|
|
|
|
|
@attrs(repr=False, frozen=True, slots=True) |
|
class _MatchesReValidator: |
|
pattern = attrib() |
|
match_func = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if not self.match_func(value): |
|
msg = "'{name}' must match regex {pattern!r} ({value!r} doesn't)".format( |
|
name=attr.name, pattern=self.pattern.pattern, value=value |
|
) |
|
raise ValueError( |
|
msg, |
|
attr, |
|
self.pattern, |
|
value, |
|
) |
|
|
|
def __repr__(self): |
|
return f"<matches_re validator for pattern {self.pattern!r}>" |
|
|
|
|
|
def matches_re(regex, flags=0, func=None): |
|
r""" |
|
A validator that raises `ValueError` if the initializer is called |
|
with a string that doesn't match *regex*. |
|
|
|
:param regex: a regex string or precompiled pattern to match against |
|
:param int flags: flags that will be passed to the underlying re function |
|
(default 0) |
|
:param callable func: which underlying `re` function to call. Valid options |
|
are `re.fullmatch`, `re.search`, and `re.match`; the default ``None`` |
|
means `re.fullmatch`. For performance reasons, the pattern is always |
|
precompiled using `re.compile`. |
|
|
|
.. versionadded:: 19.2.0 |
|
.. versionchanged:: 21.3.0 *regex* can be a pre-compiled pattern. |
|
""" |
|
valid_funcs = (re.fullmatch, None, re.search, re.match) |
|
if func not in valid_funcs: |
|
msg = "'func' must be one of {}.".format( |
|
", ".join( |
|
sorted(e and e.__name__ or "None" for e in set(valid_funcs)) |
|
) |
|
) |
|
raise ValueError(msg) |
|
|
|
if isinstance(regex, Pattern): |
|
if flags: |
|
msg = "'flags' can only be used with a string pattern; pass flags to re.compile() instead" |
|
raise TypeError(msg) |
|
pattern = regex |
|
else: |
|
pattern = re.compile(regex, flags) |
|
|
|
if func is re.match: |
|
match_func = pattern.match |
|
elif func is re.search: |
|
match_func = pattern.search |
|
else: |
|
match_func = pattern.fullmatch |
|
|
|
return _MatchesReValidator(pattern, match_func) |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _ProvidesValidator: |
|
interface = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if not self.interface.providedBy(value): |
|
msg = "'{name}' must provide {interface!r} which {value!r} doesn't.".format( |
|
name=attr.name, interface=self.interface, value=value |
|
) |
|
raise TypeError( |
|
msg, |
|
attr, |
|
self.interface, |
|
value, |
|
) |
|
|
|
def __repr__(self): |
|
return f"<provides validator for interface {self.interface!r}>" |
|
|
|
|
|
def provides(interface): |
|
""" |
|
A validator that raises a `TypeError` if the initializer is called |
|
with an object that does not provide the requested *interface* (checks are |
|
performed using ``interface.providedBy(value)`` (see `zope.interface |
|
<https://zopeinterface.readthedocs.io/en/latest/>`_). |
|
|
|
:param interface: The interface to check for. |
|
:type interface: ``zope.interface.Interface`` |
|
|
|
:raises TypeError: With a human readable error message, the attribute |
|
(of type `attrs.Attribute`), the expected interface, and the |
|
value it got. |
|
|
|
.. deprecated:: 23.1.0 |
|
""" |
|
import warnings |
|
|
|
warnings.warn( |
|
"attrs's zope-interface support is deprecated and will be removed in, " |
|
"or after, April 2024.", |
|
DeprecationWarning, |
|
stacklevel=2, |
|
) |
|
return _ProvidesValidator(interface) |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _OptionalValidator: |
|
validator = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
if value is None: |
|
return |
|
|
|
self.validator(inst, attr, value) |
|
|
|
def __repr__(self): |
|
return f"<optional validator for {self.validator!r} or None>" |
|
|
|
|
|
def optional(validator): |
|
""" |
|
A validator that makes an attribute optional. An optional attribute is one |
|
which can be set to ``None`` in addition to satisfying the requirements of |
|
the sub-validator. |
|
|
|
:param Callable | tuple[Callable] | list[Callable] validator: A validator |
|
(or validators) that is used for non-``None`` values. |
|
|
|
.. versionadded:: 15.1.0 |
|
.. versionchanged:: 17.1.0 *validator* can be a list of validators. |
|
.. versionchanged:: 23.1.0 *validator* can also be a tuple of validators. |
|
""" |
|
if isinstance(validator, (list, tuple)): |
|
return _OptionalValidator(_AndValidator(validator)) |
|
|
|
return _OptionalValidator(validator) |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _InValidator: |
|
options = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
try: |
|
in_options = value in self.options |
|
except TypeError: |
|
in_options = False |
|
|
|
if not in_options: |
|
msg = f"'{attr.name}' must be in {self.options!r} (got {value!r})" |
|
raise ValueError( |
|
msg, |
|
attr, |
|
self.options, |
|
value, |
|
) |
|
|
|
def __repr__(self): |
|
return f"<in_ validator with options {self.options!r}>" |
|
|
|
|
|
def in_(options): |
|
""" |
|
A validator that raises a `ValueError` if the initializer is called |
|
with a value that does not belong in the options provided. The check is |
|
performed using ``value in options``. |
|
|
|
:param options: Allowed options. |
|
:type options: list, tuple, `enum.Enum`, ... |
|
|
|
:raises ValueError: With a human readable error message, the attribute (of |
|
type `attrs.Attribute`), the expected options, and the value it |
|
got. |
|
|
|
.. versionadded:: 17.1.0 |
|
.. versionchanged:: 22.1.0 |
|
The ValueError was incomplete until now and only contained the human |
|
readable error message. Now it contains all the information that has |
|
been promised since 17.1.0. |
|
""" |
|
return _InValidator(options) |
|
|
|
|
|
@attrs(repr=False, slots=False, hash=True) |
|
class _IsCallableValidator: |
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if not callable(value): |
|
message = ( |
|
"'{name}' must be callable " |
|
"(got {value!r} that is a {actual!r})." |
|
) |
|
raise NotCallableError( |
|
msg=message.format( |
|
name=attr.name, value=value, actual=value.__class__ |
|
), |
|
value=value, |
|
) |
|
|
|
def __repr__(self): |
|
return "<is_callable validator>" |
|
|
|
|
|
def is_callable(): |
|
""" |
|
A validator that raises a `attrs.exceptions.NotCallableError` if the |
|
initializer is called with a value for this particular attribute |
|
that is not callable. |
|
|
|
.. versionadded:: 19.1.0 |
|
|
|
:raises attrs.exceptions.NotCallableError: With a human readable error |
|
message containing the attribute (`attrs.Attribute`) name, |
|
and the value it got. |
|
""" |
|
return _IsCallableValidator() |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _DeepIterable: |
|
member_validator = attrib(validator=is_callable()) |
|
iterable_validator = attrib( |
|
default=None, validator=optional(is_callable()) |
|
) |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if self.iterable_validator is not None: |
|
self.iterable_validator(inst, attr, value) |
|
|
|
for member in value: |
|
self.member_validator(inst, attr, member) |
|
|
|
def __repr__(self): |
|
iterable_identifier = ( |
|
"" |
|
if self.iterable_validator is None |
|
else f" {self.iterable_validator!r}" |
|
) |
|
return ( |
|
f"<deep_iterable validator for{iterable_identifier}" |
|
f" iterables of {self.member_validator!r}>" |
|
) |
|
|
|
|
|
def deep_iterable(member_validator, iterable_validator=None): |
|
""" |
|
A validator that performs deep validation of an iterable. |
|
|
|
:param member_validator: Validator(s) to apply to iterable members |
|
:param iterable_validator: Validator to apply to iterable itself |
|
(optional) |
|
|
|
.. versionadded:: 19.1.0 |
|
|
|
:raises TypeError: if any sub-validators fail |
|
""" |
|
if isinstance(member_validator, (list, tuple)): |
|
member_validator = and_(*member_validator) |
|
return _DeepIterable(member_validator, iterable_validator) |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _DeepMapping: |
|
key_validator = attrib(validator=is_callable()) |
|
value_validator = attrib(validator=is_callable()) |
|
mapping_validator = attrib(default=None, validator=optional(is_callable())) |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if self.mapping_validator is not None: |
|
self.mapping_validator(inst, attr, value) |
|
|
|
for key in value: |
|
self.key_validator(inst, attr, key) |
|
self.value_validator(inst, attr, value[key]) |
|
|
|
def __repr__(self): |
|
return ( |
|
"<deep_mapping validator for objects mapping {key!r} to {value!r}>" |
|
).format(key=self.key_validator, value=self.value_validator) |
|
|
|
|
|
def deep_mapping(key_validator, value_validator, mapping_validator=None): |
|
""" |
|
A validator that performs deep validation of a dictionary. |
|
|
|
:param key_validator: Validator to apply to dictionary keys |
|
:param value_validator: Validator to apply to dictionary values |
|
:param mapping_validator: Validator to apply to top-level mapping |
|
attribute (optional) |
|
|
|
.. versionadded:: 19.1.0 |
|
|
|
:raises TypeError: if any sub-validators fail |
|
""" |
|
return _DeepMapping(key_validator, value_validator, mapping_validator) |
|
|
|
|
|
@attrs(repr=False, frozen=True, slots=True) |
|
class _NumberValidator: |
|
bound = attrib() |
|
compare_op = attrib() |
|
compare_func = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if not self.compare_func(value, self.bound): |
|
msg = f"'{attr.name}' must be {self.compare_op} {self.bound}: {value}" |
|
raise ValueError(msg) |
|
|
|
def __repr__(self): |
|
return f"<Validator for x {self.compare_op} {self.bound}>" |
|
|
|
|
|
def lt(val): |
|
""" |
|
A validator that raises `ValueError` if the initializer is called |
|
with a number larger or equal to *val*. |
|
|
|
:param val: Exclusive upper bound for values |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
return _NumberValidator(val, "<", operator.lt) |
|
|
|
|
|
def le(val): |
|
""" |
|
A validator that raises `ValueError` if the initializer is called |
|
with a number greater than *val*. |
|
|
|
:param val: Inclusive upper bound for values |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
return _NumberValidator(val, "<=", operator.le) |
|
|
|
|
|
def ge(val): |
|
""" |
|
A validator that raises `ValueError` if the initializer is called |
|
with a number smaller than *val*. |
|
|
|
:param val: Inclusive lower bound for values |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
return _NumberValidator(val, ">=", operator.ge) |
|
|
|
|
|
def gt(val): |
|
""" |
|
A validator that raises `ValueError` if the initializer is called |
|
with a number smaller or equal to *val*. |
|
|
|
:param val: Exclusive lower bound for values |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
return _NumberValidator(val, ">", operator.gt) |
|
|
|
|
|
@attrs(repr=False, frozen=True, slots=True) |
|
class _MaxLengthValidator: |
|
max_length = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if len(value) > self.max_length: |
|
msg = f"Length of '{attr.name}' must be <= {self.max_length}: {len(value)}" |
|
raise ValueError(msg) |
|
|
|
def __repr__(self): |
|
return f"<max_len validator for {self.max_length}>" |
|
|
|
|
|
def max_len(length): |
|
""" |
|
A validator that raises `ValueError` if the initializer is called |
|
with a string or iterable that is longer than *length*. |
|
|
|
:param int length: Maximum length of the string or iterable |
|
|
|
.. versionadded:: 21.3.0 |
|
""" |
|
return _MaxLengthValidator(length) |
|
|
|
|
|
@attrs(repr=False, frozen=True, slots=True) |
|
class _MinLengthValidator: |
|
min_length = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if len(value) < self.min_length: |
|
msg = f"Length of '{attr.name}' must be >= {self.min_length}: {len(value)}" |
|
raise ValueError(msg) |
|
|
|
def __repr__(self): |
|
return f"<min_len validator for {self.min_length}>" |
|
|
|
|
|
def min_len(length): |
|
""" |
|
A validator that raises `ValueError` if the initializer is called |
|
with a string or iterable that is shorter than *length*. |
|
|
|
:param int length: Minimum length of the string or iterable |
|
|
|
.. versionadded:: 22.1.0 |
|
""" |
|
return _MinLengthValidator(length) |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _SubclassOfValidator: |
|
type = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
""" |
|
We use a callable class to be able to change the ``__repr__``. |
|
""" |
|
if not issubclass(value, self.type): |
|
msg = f"'{attr.name}' must be a subclass of {self.type!r} (got {value!r})." |
|
raise TypeError( |
|
msg, |
|
attr, |
|
self.type, |
|
value, |
|
) |
|
|
|
def __repr__(self): |
|
return f"<subclass_of validator for type {self.type!r}>" |
|
|
|
|
|
def _subclass_of(type): |
|
""" |
|
A validator that raises a `TypeError` if the initializer is called |
|
with a wrong type for this particular attribute (checks are performed using |
|
`issubclass` therefore it's also valid to pass a tuple of types). |
|
|
|
:param type: The type to check for. |
|
:type type: type or tuple of types |
|
|
|
:raises TypeError: With a human readable error message, the attribute |
|
(of type `attrs.Attribute`), the expected type, and the value it |
|
got. |
|
""" |
|
return _SubclassOfValidator(type) |
|
|
|
|
|
@attrs(repr=False, slots=True, hash=True) |
|
class _NotValidator: |
|
validator = attrib() |
|
msg = attrib( |
|
converter=default_if_none( |
|
"not_ validator child '{validator!r}' " |
|
"did not raise a captured error" |
|
) |
|
) |
|
exc_types = attrib( |
|
validator=deep_iterable( |
|
member_validator=_subclass_of(Exception), |
|
iterable_validator=instance_of(tuple), |
|
), |
|
) |
|
|
|
def __call__(self, inst, attr, value): |
|
try: |
|
self.validator(inst, attr, value) |
|
except self.exc_types: |
|
pass |
|
else: |
|
raise ValueError( |
|
self.msg.format( |
|
validator=self.validator, |
|
exc_types=self.exc_types, |
|
), |
|
attr, |
|
self.validator, |
|
value, |
|
self.exc_types, |
|
) |
|
|
|
def __repr__(self): |
|
return ( |
|
"<not_ validator wrapping {what!r}, capturing {exc_types!r}>" |
|
).format( |
|
what=self.validator, |
|
exc_types=self.exc_types, |
|
) |
|
|
|
|
|
def not_(validator, *, msg=None, exc_types=(ValueError, TypeError)): |
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""" |
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A validator that wraps and logically 'inverts' the validator passed to it. |
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It will raise a `ValueError` if the provided validator *doesn't* raise a |
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`ValueError` or `TypeError` (by default), and will suppress the exception |
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if the provided validator *does*. |
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Intended to be used with existing validators to compose logic without |
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needing to create inverted variants, for example, ``not_(in_(...))``. |
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:param validator: A validator to be logically inverted. |
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:param msg: Message to raise if validator fails. |
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Formatted with keys ``exc_types`` and ``validator``. |
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:type msg: str |
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:param exc_types: Exception type(s) to capture. |
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Other types raised by child validators will not be intercepted and |
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pass through. |
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:raises ValueError: With a human readable error message, |
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the attribute (of type `attrs.Attribute`), |
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the validator that failed to raise an exception, |
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the value it got, |
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and the expected exception types. |
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.. versionadded:: 22.2.0 |
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""" |
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try: |
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exc_types = tuple(exc_types) |
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except TypeError: |
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exc_types = (exc_types,) |
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return _NotValidator(validator, msg, exc_types) |
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