|
|
|
|
|
""" |
|
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", |
|
"or_", |
|
"set_disabled", |
|
] |
|
|
|
|
|
def set_disabled(disabled): |
|
""" |
|
Globally disable or enable running validators. |
|
|
|
By default, they are run. |
|
|
|
Args: |
|
disabled (bool): If `True`, disable running all validators. |
|
|
|
.. 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. |
|
|
|
Returns: |
|
bool:`True` if validators are currently disabled. |
|
|
|
.. 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, unsafe_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 = f"'{attr.name}' must be {self.type!r} (got {value!r} that is a {value.__class__!r})." |
|
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). |
|
|
|
Args: |
|
type (type | tuple[type]): The type to check for. |
|
|
|
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 = f"'{attr.name}' must match regex {self.pattern.pattern!r} ({value!r} doesn't)" |
|
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*. |
|
|
|
Args: |
|
regex (str, re.Pattern): |
|
A regex string or precompiled pattern to match against |
|
|
|
flags (int): |
|
Flags that will be passed to the underlying re function (default 0) |
|
|
|
func (typing.Callable): |
|
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, unsafe_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. |
|
|
|
Args: |
|
validator |
|
(typing.Callable | tuple[typing.Callable] | list[typing.Callable]): |
|
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, unsafe_hash=True) |
|
class _InValidator: |
|
options = attrib() |
|
_original_options = attrib(hash=False) |
|
|
|
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._original_options!r} (got {value!r})" |
|
raise ValueError( |
|
msg, |
|
attr, |
|
self._original_options, |
|
value, |
|
) |
|
|
|
def __repr__(self): |
|
return f"<in_ validator with options {self._original_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``, so *options* has to |
|
support that operation. |
|
|
|
To keep the validator hashable, dicts, lists, and sets are transparently |
|
transformed into a `tuple`. |
|
|
|
Args: |
|
options: Allowed options. |
|
|
|
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. |
|
.. versionchanged:: 24.1.0 |
|
*options* that are a list, dict, or a set are now transformed into a |
|
tuple to keep the validator hashable. |
|
""" |
|
repr_options = options |
|
if isinstance(options, (list, dict, set)): |
|
options = tuple(options) |
|
|
|
return _InValidator(options, repr_options) |
|
|
|
|
|
@attrs(repr=False, slots=False, unsafe_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, unsafe_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. |
|
|
|
Args: |
|
member_validator: Validator to apply to iterable members. |
|
|
|
iterable_validator: |
|
Validator to apply to iterable itself (optional). |
|
|
|
Raises |
|
TypeError: if any sub-validators fail |
|
|
|
.. versionadded:: 19.1.0 |
|
""" |
|
if isinstance(member_validator, (list, tuple)): |
|
member_validator = and_(*member_validator) |
|
return _DeepIterable(member_validator, iterable_validator) |
|
|
|
|
|
@attrs(repr=False, slots=True, unsafe_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 f"<deep_mapping validator for objects mapping {self.key_validator!r} to {self.value_validator!r}>" |
|
|
|
|
|
def deep_mapping(key_validator, value_validator, mapping_validator=None): |
|
""" |
|
A validator that performs deep validation of a dictionary. |
|
|
|
Args: |
|
key_validator: Validator to apply to dictionary keys. |
|
|
|
value_validator: Validator to apply to dictionary values. |
|
|
|
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*. |
|
|
|
The validator uses `operator.lt` to compare the values. |
|
|
|
Args: |
|
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*. |
|
|
|
The validator uses `operator.le` to compare the values. |
|
|
|
Args: |
|
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*. |
|
|
|
The validator uses `operator.ge` to compare the values. |
|
|
|
Args: |
|
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*. |
|
|
|
The validator uses `operator.ge` to compare the values. |
|
|
|
Args: |
|
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*. |
|
|
|
Args: |
|
length (int): 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*. |
|
|
|
Args: |
|
length (int): Minimum length of the string or iterable |
|
|
|
.. versionadded:: 22.1.0 |
|
""" |
|
return _MinLengthValidator(length) |
|
|
|
|
|
@attrs(repr=False, slots=True, unsafe_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). |
|
|
|
Args: |
|
type (type | tuple[type, ...]): The type(s) to check for. |
|
|
|
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, unsafe_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 f"<not_ validator wrapping {self.validator!r}, capturing {self.exc_types!r}>" |
|
|
|
|
|
def not_(validator, *, msg=None, exc_types=(ValueError, TypeError)): |
|
""" |
|
A validator that wraps and logically 'inverts' the validator passed to it. |
|
It will raise a `ValueError` if the provided validator *doesn't* raise a |
|
`ValueError` or `TypeError` (by default), and will suppress the exception |
|
if the provided validator *does*. |
|
|
|
Intended to be used with existing validators to compose logic without |
|
needing to create inverted variants, for example, ``not_(in_(...))``. |
|
|
|
Args: |
|
validator: A validator to be logically inverted. |
|
|
|
msg (str): |
|
Message to raise if validator fails. Formatted with keys |
|
``exc_types`` and ``validator``. |
|
|
|
exc_types (tuple[type, ...]): |
|
Exception type(s) to capture. Other types raised by child |
|
validators will not be intercepted and pass through. |
|
|
|
Raises: |
|
ValueError: |
|
With a human readable error message, the attribute (of type |
|
`attrs.Attribute`), the validator that failed to raise an |
|
exception, the value it got, and the expected exception types. |
|
|
|
.. versionadded:: 22.2.0 |
|
""" |
|
try: |
|
exc_types = tuple(exc_types) |
|
except TypeError: |
|
exc_types = (exc_types,) |
|
return _NotValidator(validator, msg, exc_types) |
|
|
|
|
|
@attrs(repr=False, slots=True, unsafe_hash=True) |
|
class _OrValidator: |
|
validators = attrib() |
|
|
|
def __call__(self, inst, attr, value): |
|
for v in self.validators: |
|
try: |
|
v(inst, attr, value) |
|
except Exception: |
|
continue |
|
else: |
|
return |
|
|
|
msg = f"None of {self.validators!r} satisfied for value {value!r}" |
|
raise ValueError(msg) |
|
|
|
def __repr__(self): |
|
return f"<or validator wrapping {self.validators!r}>" |
|
|
|
|
|
def or_(*validators): |
|
""" |
|
A validator that composes multiple validators into one. |
|
|
|
When called on a value, it runs all wrapped validators until one of them is |
|
satisfied. |
|
|
|
Args: |
|
validators (~collections.abc.Iterable[typing.Callable]): |
|
Arbitrary number of validators. |
|
|
|
Raises: |
|
ValueError: |
|
If no validator is satisfied. Raised with a human-readable error |
|
message listing all the wrapped validators and the value that |
|
failed all of them. |
|
|
|
.. versionadded:: 24.1.0 |
|
""" |
|
vals = [] |
|
for v in validators: |
|
vals.extend(v.validators if isinstance(v, _OrValidator) else [v]) |
|
|
|
return _OrValidator(tuple(vals)) |
|
|