Current File : //opt/hc_python/lib64/python3.8/site-packages/pydantic/config.py
"""Configuration for Pydantic models."""
from __future__ import annotations as _annotations
from typing import TYPE_CHECKING, Any, Callable, Dict, List, Type, TypeVar, Union
from typing_extensions import Literal, TypeAlias, TypedDict
from ._migration import getattr_migration
from .aliases import AliasGenerator
from .errors import PydanticUserError
if TYPE_CHECKING:
from ._internal._generate_schema import GenerateSchema as _GenerateSchema
from .fields import ComputedFieldInfo, FieldInfo
__all__ = ('ConfigDict', 'with_config')
JsonValue: TypeAlias = Union[int, float, str, bool, None, List['JsonValue'], 'JsonDict']
JsonDict: TypeAlias = Dict[str, JsonValue]
JsonEncoder = Callable[[Any], Any]
JsonSchemaExtraCallable: TypeAlias = Union[
Callable[[JsonDict], None],
Callable[[JsonDict, Type[Any]], None],
]
ExtraValues = Literal['allow', 'ignore', 'forbid']
class ConfigDict(TypedDict, total=False):
"""A TypedDict for configuring Pydantic behaviour."""
title: str | None
"""The title for the generated JSON schema, defaults to the model's name"""
model_title_generator: Callable[[type], str] | None
"""A callable that takes a model class and returns the title for it. Defaults to `None`."""
field_title_generator: Callable[[str, FieldInfo | ComputedFieldInfo], str] | None
"""A callable that takes a field's name and info and returns title for it. Defaults to `None`."""
str_to_lower: bool
"""Whether to convert all characters to lowercase for str types. Defaults to `False`."""
str_to_upper: bool
"""Whether to convert all characters to uppercase for str types. Defaults to `False`."""
str_strip_whitespace: bool
"""Whether to strip leading and trailing whitespace for str types."""
str_min_length: int
"""The minimum length for str types. Defaults to `None`."""
str_max_length: int | None
"""The maximum length for str types. Defaults to `None`."""
extra: ExtraValues | None
"""
Whether to ignore, allow, or forbid extra attributes during model initialization. Defaults to `'ignore'`.
You can configure how pydantic handles the attributes that are not defined in the model:
* `allow` - Allow any extra attributes.
* `forbid` - Forbid any extra attributes.
* `ignore` - Ignore any extra attributes.
```py
from pydantic import BaseModel, ConfigDict
class User(BaseModel):
model_config = ConfigDict(extra='ignore') # (1)!
name: str
user = User(name='John Doe', age=20) # (2)!
print(user)
#> name='John Doe'
```
1. This is the default behaviour.
2. The `age` argument is ignored.
Instead, with `extra='allow'`, the `age` argument is included:
```py
from pydantic import BaseModel, ConfigDict
class User(BaseModel):
model_config = ConfigDict(extra='allow')
name: str
user = User(name='John Doe', age=20) # (1)!
print(user)
#> name='John Doe' age=20
```
1. The `age` argument is included.
With `extra='forbid'`, an error is raised:
```py
from pydantic import BaseModel, ConfigDict, ValidationError
class User(BaseModel):
model_config = ConfigDict(extra='forbid')
name: str
try:
User(name='John Doe', age=20)
except ValidationError as e:
print(e)
'''
1 validation error for User
age
Extra inputs are not permitted [type=extra_forbidden, input_value=20, input_type=int]
'''
```
"""
frozen: bool
"""
Whether models are faux-immutable, i.e. whether `__setattr__` is allowed, and also generates
a `__hash__()` method for the model. This makes instances of the model potentially hashable if all the
attributes are hashable. Defaults to `False`.
Note:
On V1, the inverse of this setting was called `allow_mutation`, and was `True` by default.
"""
populate_by_name: bool
"""
Whether an aliased field may be populated by its name as given by the model
attribute, as well as the alias. Defaults to `False`.
Note:
The name of this configuration setting was changed in **v2.0** from
`allow_population_by_field_name` to `populate_by_name`.
```py
from pydantic import BaseModel, ConfigDict, Field
class User(BaseModel):
model_config = ConfigDict(populate_by_name=True)
name: str = Field(alias='full_name') # (1)!
age: int
user = User(full_name='John Doe', age=20) # (2)!
print(user)
#> name='John Doe' age=20
user = User(name='John Doe', age=20) # (3)!
print(user)
#> name='John Doe' age=20
```
1. The field `'name'` has an alias `'full_name'`.
2. The model is populated by the alias `'full_name'`.
3. The model is populated by the field name `'name'`.
"""
use_enum_values: bool
"""
Whether to populate models with the `value` property of enums, rather than the raw enum.
This may be useful if you want to serialize `model.model_dump()` later. Defaults to `False`.
!!! note
If you have an `Optional[Enum]` value that you set a default for, you need to use `validate_default=True`
for said Field to ensure that the `use_enum_values` flag takes effect on the default, as extracting an
enum's value occurs during validation, not serialization.
```py
from enum import Enum
from typing import Optional
from pydantic import BaseModel, ConfigDict, Field
class SomeEnum(Enum):
FOO = 'foo'
BAR = 'bar'
BAZ = 'baz'
class SomeModel(BaseModel):
model_config = ConfigDict(use_enum_values=True)
some_enum: SomeEnum
another_enum: Optional[SomeEnum] = Field(default=SomeEnum.FOO, validate_default=True)
model1 = SomeModel(some_enum=SomeEnum.BAR)
print(model1.model_dump())
# {'some_enum': 'bar', 'another_enum': 'foo'}
model2 = SomeModel(some_enum=SomeEnum.BAR, another_enum=SomeEnum.BAZ)
print(model2.model_dump())
#> {'some_enum': 'bar', 'another_enum': 'baz'}
```
"""
validate_assignment: bool
"""
Whether to validate the data when the model is changed. Defaults to `False`.
The default behavior of Pydantic is to validate the data when the model is created.
In case the user changes the data after the model is created, the model is _not_ revalidated.
```py
from pydantic import BaseModel
class User(BaseModel):
name: str
user = User(name='John Doe') # (1)!
print(user)
#> name='John Doe'
user.name = 123 # (1)!
print(user)
#> name=123
```
1. The validation happens only when the model is created.
2. The validation does not happen when the data is changed.
In case you want to revalidate the model when the data is changed, you can use `validate_assignment=True`:
```py
from pydantic import BaseModel, ValidationError
class User(BaseModel, validate_assignment=True): # (1)!
name: str
user = User(name='John Doe') # (2)!
print(user)
#> name='John Doe'
try:
user.name = 123 # (3)!
except ValidationError as e:
print(e)
'''
1 validation error for User
name
Input should be a valid string [type=string_type, input_value=123, input_type=int]
'''
```
1. You can either use class keyword arguments, or `model_config` to set `validate_assignment=True`.
2. The validation happens when the model is created.
3. The validation _also_ happens when the data is changed.
"""
arbitrary_types_allowed: bool
"""
Whether arbitrary types are allowed for field types. Defaults to `False`.
```py
from pydantic import BaseModel, ConfigDict, ValidationError
# This is not a pydantic model, it's an arbitrary class
class Pet:
def __init__(self, name: str):
self.name = name
class Model(BaseModel):
model_config = ConfigDict(arbitrary_types_allowed=True)
pet: Pet
owner: str
pet = Pet(name='Hedwig')
# A simple check of instance type is used to validate the data
model = Model(owner='Harry', pet=pet)
print(model)
#> pet=<__main__.Pet object at 0x0123456789ab> owner='Harry'
print(model.pet)
#> <__main__.Pet object at 0x0123456789ab>
print(model.pet.name)
#> Hedwig
print(type(model.pet))
#> <class '__main__.Pet'>
try:
# If the value is not an instance of the type, it's invalid
Model(owner='Harry', pet='Hedwig')
except ValidationError as e:
print(e)
'''
1 validation error for Model
pet
Input should be an instance of Pet [type=is_instance_of, input_value='Hedwig', input_type=str]
'''
# Nothing in the instance of the arbitrary type is checked
# Here name probably should have been a str, but it's not validated
pet2 = Pet(name=42)
model2 = Model(owner='Harry', pet=pet2)
print(model2)
#> pet=<__main__.Pet object at 0x0123456789ab> owner='Harry'
print(model2.pet)
#> <__main__.Pet object at 0x0123456789ab>
print(model2.pet.name)
#> 42
print(type(model2.pet))
#> <class '__main__.Pet'>
```
"""
from_attributes: bool
"""
Whether to build models and look up discriminators of tagged unions using python object attributes.
"""
loc_by_alias: bool
"""Whether to use the actual key provided in the data (e.g. alias) for error `loc`s rather than the field's name. Defaults to `True`."""
alias_generator: Callable[[str], str] | AliasGenerator | None
"""
A callable that takes a field name and returns an alias for it
or an instance of [`AliasGenerator`][pydantic.aliases.AliasGenerator]. Defaults to `None`.
When using a callable, the alias generator is used for both validation and serialization.
If you want to use different alias generators for validation and serialization, you can use
[`AliasGenerator`][pydantic.aliases.AliasGenerator] instead.
If data source field names do not match your code style (e. g. CamelCase fields),
you can automatically generate aliases using `alias_generator`. Here's an example with
a basic callable:
```py
from pydantic import BaseModel, ConfigDict
from pydantic.alias_generators import to_pascal
class Voice(BaseModel):
model_config = ConfigDict(alias_generator=to_pascal)
name: str
language_code: str
voice = Voice(Name='Filiz', LanguageCode='tr-TR')
print(voice.language_code)
#> tr-TR
print(voice.model_dump(by_alias=True))
#> {'Name': 'Filiz', 'LanguageCode': 'tr-TR'}
```
If you want to use different alias generators for validation and serialization, you can use
[`AliasGenerator`][pydantic.aliases.AliasGenerator].
```py
from pydantic import AliasGenerator, BaseModel, ConfigDict
from pydantic.alias_generators import to_camel, to_pascal
class Athlete(BaseModel):
first_name: str
last_name: str
sport: str
model_config = ConfigDict(
alias_generator=AliasGenerator(
validation_alias=to_camel,
serialization_alias=to_pascal,
)
)
athlete = Athlete(firstName='John', lastName='Doe', sport='track')
print(athlete.model_dump(by_alias=True))
#> {'FirstName': 'John', 'LastName': 'Doe', 'Sport': 'track'}
```
Note:
Pydantic offers three built-in alias generators: [`to_pascal`][pydantic.alias_generators.to_pascal],
[`to_camel`][pydantic.alias_generators.to_camel], and [`to_snake`][pydantic.alias_generators.to_snake].
"""
ignored_types: tuple[type, ...]
"""A tuple of types that may occur as values of class attributes without annotations. This is
typically used for custom descriptors (classes that behave like `property`). If an attribute is set on a
class without an annotation and has a type that is not in this tuple (or otherwise recognized by
_pydantic_), an error will be raised. Defaults to `()`.
"""
allow_inf_nan: bool
"""Whether to allow infinity (`+inf` an `-inf`) and NaN values to float fields. Defaults to `True`."""
json_schema_extra: JsonDict | JsonSchemaExtraCallable | None
"""A dict or callable to provide extra JSON schema properties. Defaults to `None`."""
json_encoders: dict[type[object], JsonEncoder] | None
"""
A `dict` of custom JSON encoders for specific types. Defaults to `None`.
!!! warning "Deprecated"
This config option is a carryover from v1.
We originally planned to remove it in v2 but didn't have a 1:1 replacement so we are keeping it for now.
It is still deprecated and will likely be removed in the future.
"""
# new in V2
strict: bool
"""
_(new in V2)_ If `True`, strict validation is applied to all fields on the model.
By default, Pydantic attempts to coerce values to the correct type, when possible.
There are situations in which you may want to disable this behavior, and instead raise an error if a value's type
does not match the field's type annotation.
To configure strict mode for all fields on a model, you can set `strict=True` on the model.
```py
from pydantic import BaseModel, ConfigDict
class Model(BaseModel):
model_config = ConfigDict(strict=True)
name: str
age: int
```
See [Strict Mode](../concepts/strict_mode.md) for more details.
See the [Conversion Table](../concepts/conversion_table.md) for more details on how Pydantic converts data in both
strict and lax modes.
"""
# whether instances of models and dataclasses (including subclass instances) should re-validate, default 'never'
revalidate_instances: Literal['always', 'never', 'subclass-instances']
"""
When and how to revalidate models and dataclasses during validation. Accepts the string
values of `'never'`, `'always'` and `'subclass-instances'`. Defaults to `'never'`.
- `'never'` will not revalidate models and dataclasses during validation
- `'always'` will revalidate models and dataclasses during validation
- `'subclass-instances'` will revalidate models and dataclasses during validation if the instance is a
subclass of the model or dataclass
By default, model and dataclass instances are not revalidated during validation.
```py
from typing import List
from pydantic import BaseModel
class User(BaseModel, revalidate_instances='never'): # (1)!
hobbies: List[str]
class SubUser(User):
sins: List[str]
class Transaction(BaseModel):
user: User
my_user = User(hobbies=['reading'])
t = Transaction(user=my_user)
print(t)
#> user=User(hobbies=['reading'])
my_user.hobbies = [1] # (2)!
t = Transaction(user=my_user) # (3)!
print(t)
#> user=User(hobbies=[1])
my_sub_user = SubUser(hobbies=['scuba diving'], sins=['lying'])
t = Transaction(user=my_sub_user)
print(t)
#> user=SubUser(hobbies=['scuba diving'], sins=['lying'])
```
1. `revalidate_instances` is set to `'never'` by **default.
2. The assignment is not validated, unless you set `validate_assignment` to `True` in the model's config.
3. Since `revalidate_instances` is set to `never`, this is not revalidated.
If you want to revalidate instances during validation, you can set `revalidate_instances` to `'always'`
in the model's config.
```py
from typing import List
from pydantic import BaseModel, ValidationError
class User(BaseModel, revalidate_instances='always'): # (1)!
hobbies: List[str]
class SubUser(User):
sins: List[str]
class Transaction(BaseModel):
user: User
my_user = User(hobbies=['reading'])
t = Transaction(user=my_user)
print(t)
#> user=User(hobbies=['reading'])
my_user.hobbies = [1]
try:
t = Transaction(user=my_user) # (2)!
except ValidationError as e:
print(e)
'''
1 validation error for Transaction
user.hobbies.0
Input should be a valid string [type=string_type, input_value=1, input_type=int]
'''
my_sub_user = SubUser(hobbies=['scuba diving'], sins=['lying'])
t = Transaction(user=my_sub_user)
print(t) # (3)!
#> user=User(hobbies=['scuba diving'])
```
1. `revalidate_instances` is set to `'always'`.
2. The model is revalidated, since `revalidate_instances` is set to `'always'`.
3. Using `'never'` we would have gotten `user=SubUser(hobbies=['scuba diving'], sins=['lying'])`.
It's also possible to set `revalidate_instances` to `'subclass-instances'` to only revalidate instances
of subclasses of the model.
```py
from typing import List
from pydantic import BaseModel
class User(BaseModel, revalidate_instances='subclass-instances'): # (1)!
hobbies: List[str]
class SubUser(User):
sins: List[str]
class Transaction(BaseModel):
user: User
my_user = User(hobbies=['reading'])
t = Transaction(user=my_user)
print(t)
#> user=User(hobbies=['reading'])
my_user.hobbies = [1]
t = Transaction(user=my_user) # (2)!
print(t)
#> user=User(hobbies=[1])
my_sub_user = SubUser(hobbies=['scuba diving'], sins=['lying'])
t = Transaction(user=my_sub_user)
print(t) # (3)!
#> user=User(hobbies=['scuba diving'])
```
1. `revalidate_instances` is set to `'subclass-instances'`.
2. This is not revalidated, since `my_user` is not a subclass of `User`.
3. Using `'never'` we would have gotten `user=SubUser(hobbies=['scuba diving'], sins=['lying'])`.
"""
ser_json_timedelta: Literal['iso8601', 'float']
"""
The format of JSON serialized timedeltas. Accepts the string values of `'iso8601'` and
`'float'`. Defaults to `'iso8601'`.
- `'iso8601'` will serialize timedeltas to ISO 8601 durations.
- `'float'` will serialize timedeltas to the total number of seconds.
"""
ser_json_bytes: Literal['utf8', 'base64']
"""
The encoding of JSON serialized bytes. Accepts the string values of `'utf8'` and `'base64'`.
Defaults to `'utf8'`.
- `'utf8'` will serialize bytes to UTF-8 strings.
- `'base64'` will serialize bytes to URL safe base64 strings.
"""
ser_json_inf_nan: Literal['null', 'constants', 'strings']
"""
The encoding of JSON serialized infinity and NaN float values. Defaults to `'null'`.
- `'null'` will serialize infinity and NaN values as `null`.
- `'constants'` will serialize infinity and NaN values as `Infinity` and `NaN`.
- `'strings'` will serialize infinity as string `"Infinity"` and NaN as string `"NaN"`.
"""
# whether to validate default values during validation, default False
validate_default: bool
"""Whether to validate default values during validation. Defaults to `False`."""
validate_return: bool
"""whether to validate the return value from call validators. Defaults to `False`."""
protected_namespaces: tuple[str, ...]
"""
A `tuple` of strings that prevent model to have field which conflict with them.
Defaults to `('model_', )`).
Pydantic prevents collisions between model attributes and `BaseModel`'s own methods by
namespacing them with the prefix `model_`.
```py
import warnings
from pydantic import BaseModel
warnings.filterwarnings('error') # Raise warnings as errors
try:
class Model(BaseModel):
model_prefixed_field: str
except UserWarning as e:
print(e)
'''
Field "model_prefixed_field" has conflict with protected namespace "model_".
You may be able to resolve this warning by setting `model_config['protected_namespaces'] = ()`.
'''
```
You can customize this behavior using the `protected_namespaces` setting:
```py
import warnings
from pydantic import BaseModel, ConfigDict
warnings.filterwarnings('error') # Raise warnings as errors
try:
class Model(BaseModel):
model_prefixed_field: str
also_protect_field: str
model_config = ConfigDict(
protected_namespaces=('protect_me_', 'also_protect_')
)
except UserWarning as e:
print(e)
'''
Field "also_protect_field" has conflict with protected namespace "also_protect_".
You may be able to resolve this warning by setting `model_config['protected_namespaces'] = ('protect_me_',)`.
'''
```
While Pydantic will only emit a warning when an item is in a protected namespace but does not actually have a collision,
an error _is_ raised if there is an actual collision with an existing attribute:
```py
from pydantic import BaseModel
try:
class Model(BaseModel):
model_validate: str
except NameError as e:
print(e)
'''
Field "model_validate" conflicts with member <bound method BaseModel.model_validate of <class 'pydantic.main.BaseModel'>> of protected namespace "model_".
'''
```
"""
hide_input_in_errors: bool
"""
Whether to hide inputs when printing errors. Defaults to `False`.
Pydantic shows the input value and type when it raises `ValidationError` during the validation.
```py
from pydantic import BaseModel, ValidationError
class Model(BaseModel):
a: str
try:
Model(a=123)
except ValidationError as e:
print(e)
'''
1 validation error for Model
a
Input should be a valid string [type=string_type, input_value=123, input_type=int]
'''
```
You can hide the input value and type by setting the `hide_input_in_errors` config to `True`.
```py
from pydantic import BaseModel, ConfigDict, ValidationError
class Model(BaseModel):
a: str
model_config = ConfigDict(hide_input_in_errors=True)
try:
Model(a=123)
except ValidationError as e:
print(e)
'''
1 validation error for Model
a
Input should be a valid string [type=string_type]
'''
```
"""
defer_build: bool
"""
Whether to defer model validator and serializer construction until the first model validation. Defaults to False.
This can be useful to avoid the overhead of building models which are only
used nested within other models, or when you want to manually define type namespace via
[`Model.model_rebuild(_types_namespace=...)`][pydantic.BaseModel.model_rebuild].
See also [`experimental_defer_build_mode`][pydantic.config.ConfigDict.experimental_defer_build_mode].
!!! note
`defer_build` does not work by default with FastAPI Pydantic models. By default, the validator and serializer
for said models is constructed immediately for FastAPI routes. You also need to define
[`experimental_defer_build_mode=('model', 'type_adapter')`][pydantic.config.ConfigDict.experimental_defer_build_mode] with FastAPI
models in order for `defer_build=True` to take effect. This additional (experimental) parameter is required for
the deferred building due to FastAPI relying on `TypeAdapter`s.
"""
experimental_defer_build_mode: tuple[Literal['model', 'type_adapter'], ...]
"""
Controls when [`defer_build`][pydantic.config.ConfigDict.defer_build] is applicable. Defaults to `('model',)`.
Due to backwards compatibility reasons [`TypeAdapter`][pydantic.type_adapter.TypeAdapter] does not by default
respect `defer_build`. Meaning when `defer_build` is `True` and `experimental_defer_build_mode` is the default `('model',)`
then `TypeAdapter` immediately constructs its validator and serializer instead of postponing said construction until
the first model validation. Set this to `('model', 'type_adapter')` to make `TypeAdapter` respect the `defer_build`
so it postpones validator and serializer construction until the first validation or serialization.
!!! note
The `experimental_defer_build_mode` parameter is named with an underscore to suggest this is an experimental feature. It may
be removed or changed in the future in a minor release.
"""
plugin_settings: dict[str, object] | None
"""A `dict` of settings for plugins. Defaults to `None`.
See [Pydantic Plugins](../concepts/plugins.md) for details.
"""
schema_generator: type[_GenerateSchema] | None
"""
A custom core schema generator class to use when generating JSON schemas.
Useful if you want to change the way types are validated across an entire model/schema. Defaults to `None`.
The `GenerateSchema` interface is subject to change, currently only the `string_schema` method is public.
See [#6737](https://github.com/pydantic/pydantic/pull/6737) for details.
"""
json_schema_serialization_defaults_required: bool
"""
Whether fields with default values should be marked as required in the serialization schema. Defaults to `False`.
This ensures that the serialization schema will reflect the fact a field with a default will always be present
when serializing the model, even though it is not required for validation.
However, there are scenarios where this may be undesirable — in particular, if you want to share the schema
between validation and serialization, and don't mind fields with defaults being marked as not required during
serialization. See [#7209](https://github.com/pydantic/pydantic/issues/7209) for more details.
```py
from pydantic import BaseModel, ConfigDict
class Model(BaseModel):
a: str = 'a'
model_config = ConfigDict(json_schema_serialization_defaults_required=True)
print(Model.model_json_schema(mode='validation'))
'''
{
'properties': {'a': {'default': 'a', 'title': 'A', 'type': 'string'}},
'title': 'Model',
'type': 'object',
}
'''
print(Model.model_json_schema(mode='serialization'))
'''
{
'properties': {'a': {'default': 'a', 'title': 'A', 'type': 'string'}},
'required': ['a'],
'title': 'Model',
'type': 'object',
}
'''
```
"""
json_schema_mode_override: Literal['validation', 'serialization', None]
"""
If not `None`, the specified mode will be used to generate the JSON schema regardless of what `mode` was passed to
the function call. Defaults to `None`.
This provides a way to force the JSON schema generation to reflect a specific mode, e.g., to always use the
validation schema.
It can be useful when using frameworks (such as FastAPI) that may generate different schemas for validation
and serialization that must both be referenced from the same schema; when this happens, we automatically append
`-Input` to the definition reference for the validation schema and `-Output` to the definition reference for the
serialization schema. By specifying a `json_schema_mode_override` though, this prevents the conflict between
the validation and serialization schemas (since both will use the specified schema), and so prevents the suffixes
from being added to the definition references.
```py
from pydantic import BaseModel, ConfigDict, Json
class Model(BaseModel):
a: Json[int] # requires a string to validate, but will dump an int
print(Model.model_json_schema(mode='serialization'))
'''
{
'properties': {'a': {'title': 'A', 'type': 'integer'}},
'required': ['a'],
'title': 'Model',
'type': 'object',
}
'''
class ForceInputModel(Model):
# the following ensures that even with mode='serialization', we
# will get the schema that would be generated for validation.
model_config = ConfigDict(json_schema_mode_override='validation')
print(ForceInputModel.model_json_schema(mode='serialization'))
'''
{
'properties': {
'a': {
'contentMediaType': 'application/json',
'contentSchema': {'type': 'integer'},
'title': 'A',
'type': 'string',
}
},
'required': ['a'],
'title': 'ForceInputModel',
'type': 'object',
}
'''
```
"""
coerce_numbers_to_str: bool
"""
If `True`, enables automatic coercion of any `Number` type to `str` in "lax" (non-strict) mode. Defaults to `False`.
Pydantic doesn't allow number types (`int`, `float`, `Decimal`) to be coerced as type `str` by default.
```py
from decimal import Decimal
from pydantic import BaseModel, ConfigDict, ValidationError
class Model(BaseModel):
value: str
try:
print(Model(value=42))
except ValidationError as e:
print(e)
'''
1 validation error for Model
value
Input should be a valid string [type=string_type, input_value=42, input_type=int]
'''
class Model(BaseModel):
model_config = ConfigDict(coerce_numbers_to_str=True)
value: str
repr(Model(value=42).value)
#> "42"
repr(Model(value=42.13).value)
#> "42.13"
repr(Model(value=Decimal('42.13')).value)
#> "42.13"
```
"""
regex_engine: Literal['rust-regex', 'python-re']
"""
The regex engine to be used for pattern validation.
Defaults to `'rust-regex'`.
- `rust-regex` uses the [`regex`](https://docs.rs/regex) Rust crate,
which is non-backtracking and therefore more DDoS resistant, but does not support all regex features.
- `python-re` use the [`re`](https://docs.python.org/3/library/re.html) module,
which supports all regex features, but may be slower.
!!! note
If you use a compiled regex pattern, the python-re engine will be used regardless of this setting.
This is so that flags such as `re.IGNORECASE` are respected.
```py
from pydantic import BaseModel, ConfigDict, Field, ValidationError
class Model(BaseModel):
model_config = ConfigDict(regex_engine='python-re')
value: str = Field(pattern=r'^abc(?=def)')
print(Model(value='abcdef').value)
#> abcdef
try:
print(Model(value='abxyzcdef'))
except ValidationError as e:
print(e)
'''
1 validation error for Model
value
String should match pattern '^abc(?=def)' [type=string_pattern_mismatch, input_value='abxyzcdef', input_type=str]
'''
```
"""
validation_error_cause: bool
"""
If `True`, Python exceptions that were part of a validation failure will be shown as an exception group as a cause. Can be useful for debugging. Defaults to `False`.
Note:
Python 3.10 and older don't support exception groups natively. <=3.10, backport must be installed: `pip install exceptiongroup`.
Note:
The structure of validation errors are likely to change in future Pydantic versions. Pydantic offers no guarantees about their structure. Should be used for visual traceback debugging only.
"""
use_attribute_docstrings: bool
'''
Whether docstrings of attributes (bare string literals immediately following the attribute declaration)
should be used for field descriptions. Defaults to `False`.
Available in Pydantic v2.7+.
```py
from pydantic import BaseModel, ConfigDict, Field
class Model(BaseModel):
model_config = ConfigDict(use_attribute_docstrings=True)
x: str
"""
Example of an attribute docstring
"""
y: int = Field(description="Description in Field")
"""
Description in Field overrides attribute docstring
"""
print(Model.model_fields["x"].description)
# > Example of an attribute docstring
print(Model.model_fields["y"].description)
# > Description in Field
```
This requires the source code of the class to be available at runtime.
!!! warning "Usage with `TypedDict`"
Due to current limitations, attribute docstrings detection may not work as expected when using `TypedDict`
(in particular when multiple `TypedDict` classes have the same name in the same source file). The behavior
can be different depending on the Python version used.
'''
cache_strings: bool | Literal['all', 'keys', 'none']
"""
Whether to cache strings to avoid constructing new Python objects. Defaults to True.
Enabling this setting should significantly improve validation performance while increasing memory usage slightly.
- `True` or `'all'` (the default): cache all strings
- `'keys'`: cache only dictionary keys
- `False` or `'none'`: no caching
!!! note
`True` or `'all'` is required to cache strings during general validation because
validators don't know if they're in a key or a value.
!!! tip
If repeated strings are rare, it's recommended to use `'keys'` or `'none'` to reduce memory usage,
as the performance difference is minimal if repeated strings are rare.
"""
_TypeT = TypeVar('_TypeT', bound=type)
def with_config(config: ConfigDict) -> Callable[[_TypeT], _TypeT]:
"""Usage docs: https://docs.pydantic.dev/2.8/concepts/config/#configuration-with-dataclass-from-the-standard-library-or-typeddict
A convenience decorator to set a [Pydantic configuration](config.md) on a `TypedDict` or a `dataclass` from the standard library.
Although the configuration can be set using the `__pydantic_config__` attribute, it does not play well with type checkers,
especially with `TypedDict`.
!!! example "Usage"
```py
from typing_extensions import TypedDict
from pydantic import ConfigDict, TypeAdapter, with_config
@with_config(ConfigDict(str_to_lower=True))
class Model(TypedDict):
x: str
ta = TypeAdapter(Model)
print(ta.validate_python({'x': 'ABC'}))
#> {'x': 'abc'}
```
"""
def inner(class_: _TypeT, /) -> _TypeT:
# Ideally, we would check for `class_` to either be a `TypedDict` or a stdlib dataclass.
# However, the `@with_config` decorator can be applied *after* `@dataclass`. To avoid
# common mistakes, we at least check for `class_` to not be a Pydantic model.
from ._internal._utils import is_model_class
if is_model_class(class_):
raise PydanticUserError(
f'Cannot use `with_config` on {class_.__name__} as it is a Pydantic model',
code='with-config-on-model',
)
class_.__pydantic_config__ = config
return class_
return inner
__getattr__ = getattr_migration(__name__)
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