pydantic_core
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pydantic_core
Section titled “pydantic_core”SchemaValidator
Section titled “SchemaValidator”SchemaValidator is the Python wrapper for pydantic-core's Rust validation logic, internally it owns one CombinedValidator which may in turn own more CombinedValidators which make up the full schema validator.
Attributes
Section titled “Attributes”The title of the schema, as used in the heading of ValidationError.__str__().
Type: str
Methods
Section titled “Methods”validate_python
Section titled “validate_python”def validate_python(
input: Any,
*,
strict: bool | None = None,
extra: ExtraBehavior | None = None,
from_attributes: bool | None = None,
context: Any | None = None,
self_instance: Any | None = None,
allow_partial: bool | Literal['off', 'on', 'trailing-strings'] = False,
by_alias: bool | None = None,
by_name: bool | None = None,
) -> AnyValidate a Python object against the schema and return the validated object.
Returns
Section titled “Returns”Any -- The validated object.
Parameters
Section titled “Parameters”input : Any
The Python object to validate.
strict : bool | None Default: None
Whether to validate the object in strict mode. If None, the value of CoreConfig.strict is used.
extra : ExtraBehavior | None Default: None
Whether to ignore, allow, or forbid extra data during model validation. If None, the value of CoreConfig.extra_fields_behavior is used.
from_attributes : bool | None Default: None
Whether to validate objects as inputs to models by extracting attributes. If None, the value of CoreConfig.from_attributes is used.
context : Any | None Default: None
The context to use for validation, this is passed to functional validators as info.context.
self_instance : Any | None Default: None
An instance of a model set attributes on from validation, this is used when running validation from the __init__ method of a model.
allow_partial : bool | Literal['off', 'on', 'trailing-strings'] Default: False
Whether to allow partial validation; if True errors in the last element of sequences and mappings are ignored. 'trailing-strings' means any final unfinished JSON string is included in the result.
by_alias : bool | None Default: None
Whether to use the field's alias when validating against the provided input data.
by_name : bool | None Default: None
Whether to use the field's name when validating against the provided input data.
Raises
Section titled “Raises”ValidationError-- If validation fails.Exception-- Other error types maybe raised if internal errors occur.
isinstance_python
Section titled “isinstance_python”def isinstance_python(
input: Any,
*,
strict: bool | None = None,
extra: ExtraBehavior | None = None,
from_attributes: bool | None = None,
context: Any | None = None,
self_instance: Any | None = None,
by_alias: bool | None = None,
by_name: bool | None = None,
) -> boolSimilar to validate_python() but returns a boolean.
Arguments match validate_python(). This method will not raise ValidationErrors but will raise internal errors.
Returns
Section titled “Returns”bool -- True if validation succeeds, False if validation fails.
validate_json
Section titled “validate_json”def validate_json(
input: str | bytes | bytearray,
*,
strict: bool | None = None,
extra: ExtraBehavior | None = None,
context: Any | None = None,
self_instance: Any | None = None,
allow_partial: bool | Literal['off', 'on', 'trailing-strings'] = False,
by_alias: bool | None = None,
by_name: bool | None = None,
) -> AnyValidate JSON data directly against the schema and return the validated Python object.
This method should be significantly faster than validate_python(json.loads(json_data)) as it avoids the need to create intermediate Python objects
It also handles constructing the correct Python type even in strict mode, where validate_python(json.loads(json_data)) would fail validation.
Returns
Section titled “Returns”Any -- The validated Python object.
Parameters
Section titled “Parameters”input : str | bytes | bytearray
The JSON data to validate.
strict : bool | None Default: None
Whether to validate the object in strict mode. If None, the value of CoreConfig.strict is used.
extra : ExtraBehavior | None Default: None
Whether to ignore, allow, or forbid extra data during model validation. If None, the value of CoreConfig.extra_fields_behavior is used.
context : Any | None Default: None
The context to use for validation, this is passed to functional validators as info.context.
self_instance : Any | None Default: None
An instance of a model set attributes on from validation.
allow_partial : bool | Literal['off', 'on', 'trailing-strings'] Default: False
Whether to allow partial validation; if True incomplete JSON will be parsed successfully and errors in the last element of sequences and mappings are ignored. 'trailing-strings' means any final unfinished JSON string is included in the result.
by_alias : bool | None Default: None
Whether to use the field's alias when validating against the provided input data.
by_name : bool | None Default: None
Whether to use the field's name when validating against the provided input data.
Raises
Section titled “Raises”ValidationError-- If validation fails or if the JSON data is invalid.Exception-- Other error types maybe raised if internal errors occur.
validate_strings
Section titled “validate_strings”def validate_strings(
input: _StringInput,
*,
strict: bool | None = None,
extra: ExtraBehavior | None = None,
context: Any | None = None,
allow_partial: bool | Literal['off', 'on', 'trailing-strings'] = False,
by_alias: bool | None = None,
by_name: bool | None = None,
) -> AnyValidate a string against the schema and return the validated Python object.
This is similar to validate_json but applies to scenarios where the input will be a string but not JSON data, e.g. URL fragments, query parameters, etc.
Returns
Section titled “Returns”Any -- The validated Python object.
Parameters
Section titled “Parameters”input : _StringInput
The input as a string, or bytes/bytearray if strict=False.
strict : bool | None Default: None
Whether to validate the object in strict mode. If None, the value of CoreConfig.strict is used.
extra : ExtraBehavior | None Default: None
Whether to ignore, allow, or forbid extra data during model validation. If None, the value of CoreConfig.extra_fields_behavior is used.
context : Any | None Default: None
The context to use for validation, this is passed to functional validators as info.context.
allow_partial : bool | Literal['off', 'on', 'trailing-strings'] Default: False
Whether to allow partial validation; if True errors in the last element of sequences and mappings are ignored. 'trailing-strings' means any final unfinished JSON string is included in the result.
by_alias : bool | None Default: None
Whether to use the field's alias when validating against the provided input data.
by_name : bool | None Default: None
Whether to use the field's name when validating against the provided input data.
Raises
Section titled “Raises”ValidationError-- If validation fails or if the JSON data is invalid.Exception-- Other error types maybe raised if internal errors occur.
validate_assignment
Section titled “validate_assignment”def validate_assignment(
obj: Any,
field_name: str,
field_value: Any,
*,
strict: bool | None = None,
extra: ExtraBehavior | None = None,
from_attributes: bool | None = None,
context: Any | None = None,
by_alias: bool | None = None,
by_name: bool | None = None,
) -> dict[str, Any] | tuple[dict[str, Any], dict[str, Any] | None, set[str]]Validate an assignment to a field on a model.
Returns
Section titled “Returns”dict[str, Any] | tuple[dict[str, Any], dict[str, Any] | None, set[str]] -- Either the model dict or a tuple of (model_data, model_extra, fields_set)
Parameters
Section titled “Parameters”obj : Any
The model instance being assigned to.
field_name : str
The name of the field to validate assignment for.
field_value : Any
The value to assign to the field.
strict : bool | None Default: None
Whether to validate the object in strict mode. If None, the value of CoreConfig.strict is used.
extra : ExtraBehavior | None Default: None
Whether to ignore, allow, or forbid extra data during model validation. If None, the value of CoreConfig.extra_fields_behavior is used.
from_attributes : bool | None Default: None
Whether to validate objects as inputs to models by extracting attributes. If None, the value of CoreConfig.from_attributes is used.
context : Any | None Default: None
The context to use for validation, this is passed to functional validators as info.context.
by_alias : bool | None Default: None
Whether to use the field's alias when validating against the provided input data.
by_name : bool | None Default: None
Whether to use the field's name when validating against the provided input data.
Raises
Section titled “Raises”ValidationError-- If validation fails.Exception-- Other error types maybe raised if internal errors occur.
get_default_value
Section titled “get_default_value”def get_default_value(*, strict: bool | None = None, context: Any = None) -> Some | NoneGet the default value for the schema, including running default value validation.
Returns
Section titled “Returns”Some | None -- None if the schema has no default value, otherwise a Some containing the default.
Parameters
Section titled “Parameters”strict : bool | None Default: None
Whether to validate the default value in strict mode. If None, the value of CoreConfig.strict is used.
context : Any Default: None
The context to use for validation, this is passed to functional validators as info.context.
Raises
Section titled “Raises”ValidationError-- If validation fails.Exception-- Other error types maybe raised if internal errors occur.
SchemaSerializer
Section titled “SchemaSerializer”SchemaSerializer is the Python wrapper for pydantic-core's Rust serialization logic, internally it owns one CombinedSerializer which may in turn own more CombinedSerializers which make up the full schema serializer.
Methods
Section titled “Methods”to_python
Section titled “to_python”def to_python(
value: Any,
*,
mode: str | None = None,
include: _IncEx | None = None,
exclude: _IncEx | None = None,
by_alias: bool | None = None,
exclude_unset: bool = False,
exclude_defaults: bool = False,
exclude_none: bool = False,
exclude_computed_fields: bool = False,
round_trip: bool = False,
warnings: bool | Literal['none', 'warn', 'error'] = True,
fallback: Callable[[Any], Any] | None = None,
serialize_as_any: bool = False,
polymorphic_serialization: bool | None = None,
context: Any | None = None,
) -> AnySerialize/marshal a Python object to a Python object including transforming and filtering data.
Returns
Section titled “Returns”Any -- The serialized Python object.
Parameters
Section titled “Parameters”value : Any
The Python object to serialize.
mode : str | None Default: None
The serialization mode to use, either 'python' or 'json', defaults to 'python'. In JSON mode, all values are converted to JSON compatible types, e.g. None, int, float, str, list, dict.
include : _IncEx | None Default: None
A set of fields to include, if None all fields are included.
exclude : _IncEx | None Default: None
A set of fields to exclude, if None no fields are excluded.
by_alias : bool | None Default: None
Whether to use the alias names of fields.
exclude_unset : bool Default: False
Whether to exclude fields that are not set, e.g. are not included in __pydantic_fields_set__.
exclude_defaults : bool Default: False
Whether to exclude fields that are equal to their default value.
exclude_none : bool Default: False
Whether to exclude fields that have a value of None.
exclude_computed_fields : bool Default: False
Whether to exclude computed fields.
round_trip : bool Default: False
Whether to enable serialization and validation round-trip support.
warnings : bool | Literal['none', 'warn', 'error'] Default: True
How to handle invalid fields. False/"none" ignores them, True/"warn" logs errors, "error" raises a PydanticSerializationError.
fallback : Callable[[Any], Any] | None Default: None
A function to call when an unknown value is encountered, if None a PydanticSerializationError error is raised.
serialize_as_any : bool Default: False
Whether to serialize fields with duck-typing serialization behavior.
polymorphic_serialization : bool | None Default: None
Whether to use model and dataclass polymorphic serialization for this call.
context : Any | None Default: None
The context to use for serialization, this is passed to functional serializers as info.context.
Raises
Section titled “Raises”PydanticSerializationError-- If serialization fails and nofallbackfunction is provided.
to_json
Section titled “to_json”def to_json(
value: Any,
*,
indent: int | None = None,
ensure_ascii: bool = False,
include: _IncEx | None = None,
exclude: _IncEx | None = None,
by_alias: bool | None = None,
exclude_unset: bool = False,
exclude_defaults: bool = False,
exclude_none: bool = False,
exclude_computed_fields: bool = False,
round_trip: bool = False,
warnings: bool | Literal['none', 'warn', 'error'] = True,
fallback: Callable[[Any], Any] | None = None,
serialize_as_any: bool = False,
polymorphic_serialization: bool | None = None,
context: Any | None = None,
) -> bytesSerialize a Python object to JSON including transforming and filtering data.
Returns
Section titled “Returns”bytes -- JSON bytes.
Parameters
Section titled “Parameters”value : Any
The Python object to serialize.
indent : int | None Default: None
If None, the JSON will be compact, otherwise it will be pretty-printed with the indent provided.
ensure_ascii : bool Default: False
If True, the output is guaranteed to have all incoming non-ASCII characters escaped. If False (the default), these characters will be output as-is.
include : _IncEx | None Default: None
A set of fields to include, if None all fields are included.
exclude : _IncEx | None Default: None
A set of fields to exclude, if None no fields are excluded.
by_alias : bool | None Default: None
Whether to use the alias names of fields.
exclude_unset : bool Default: False
Whether to exclude fields that are not set, e.g. are not included in __pydantic_fields_set__.
exclude_defaults : bool Default: False
Whether to exclude fields that are equal to their default value.
exclude_none : bool Default: False
Whether to exclude fields that have a value of None.
exclude_computed_fields : bool Default: False
Whether to exclude computed fields.
round_trip : bool Default: False
Whether to enable serialization and validation round-trip support.
warnings : bool | Literal['none', 'warn', 'error'] Default: True
How to handle invalid fields. False/"none" ignores them, True/"warn" logs errors, "error" raises a PydanticSerializationError.
fallback : Callable[[Any], Any] | None Default: None
A function to call when an unknown value is encountered, if None a PydanticSerializationError error is raised.
serialize_as_any : bool Default: False
Whether to serialize fields with duck-typing serialization behavior.
polymorphic_serialization : bool | None Default: None
Whether to use model and dataclass polymorphic serialization for this call.
context : Any | None Default: None
The context to use for serialization, this is passed to functional serializers as info.context.
Raises
Section titled “Raises”PydanticSerializationError-- If serialization fails and nofallbackfunction is provided.
ValidationError
Section titled “ValidationError”Bases: ValueError
ValidationError is the exception raised by pydantic-core when validation fails, it contains a list of errors which detail why validation failed.
Attributes
Section titled “Attributes”The title of the error, as used in the heading of str(validation_error).
Type: str
Methods
Section titled “Methods”from_exception_data
Section titled “from_exception_data”@classmethod
def from_exception_data(
cls,
title: str,
line_errors: list[InitErrorDetails],
input_type: Literal['python', 'json'] = 'python',
hide_input: bool = False,
) -> SelfPython constructor for a Validation Error.
Returns
Section titled “Returns”Parameters
Section titled “Parameters”title : str
The title of the error, as used in the heading of str(validation_error)
line_errors : list[InitErrorDetails]
A list of InitErrorDetails which contain information about errors that occurred during validation.
input_type : Literal['python', 'json'] Default: 'python'
Whether the error is for a Python object or JSON.
hide_input : bool Default: False
Whether to hide the input value in the error message.
error_count
Section titled “error_count”def error_count() -> intReturns
Section titled “Returns”int -- The number of errors in the validation error.
errors
Section titled “errors”def errors(
*,
include_url: bool = True,
include_context: bool = True,
include_input: bool = True,
) -> list[ErrorDetails]Details about each error in the validation error.
Returns
Section titled “Returns”list[ErrorDetails] -- A list of ErrorDetails for each error in the validation error.
Parameters
Section titled “Parameters”include_url : bool Default: True
Whether to include a URL to documentation on the error each error.
include_context : bool Default: True
Whether to include the context of each error.
include_input : bool Default: True
Whether to include the input value of each error.
def json(
*,
indent: int | None = None,
include_url: bool = True,
include_context: bool = True,
include_input: bool = True,
) -> strSame as errors() but returns a JSON string.
Returns
Section titled “Returns”str -- a JSON string.
Parameters
Section titled “Parameters”indent : int | None Default: None
The number of spaces to indent the JSON by, or None for no indentation - compact JSON.
include_url : bool Default: True
Whether to include a URL to documentation on the error each error.
include_context : bool Default: True
Whether to include the context of each error.
include_input : bool Default: True
Whether to include the input value of each error.
ErrorDetails
Section titled “ErrorDetails”Bases: _TypedDict
Attributes
Section titled “Attributes”The type of error that occurred, this is an identifier designed for programmatic use that will change rarely or never.
type is unique for each error message, and can hence be used as an identifier to build custom error messages.
Type: str
Tuple of strings and ints identifying where in the schema the error occurred.
A human readable error message.
Type: str
The input data at this loc that caused the error.
Type: _Any
Values which are required to render the error message, and could hence be useful in rendering custom error messages. Also useful for passing custom error data forward.
Type: _NotRequired[dict[str, _Any]]
The documentation URL giving information about the error. No URL is available if a PydanticCustomError is used.
Type: _NotRequired[str]
InitErrorDetails
Section titled “InitErrorDetails”Bases: _TypedDict
Attributes
Section titled “Attributes”The type of error that occurred, this should be a "slug" identifier that changes rarely or never.
Type: str | PydanticCustomError
Tuple of strings and ints identifying where in the schema the error occurred.
Type: _NotRequired[tuple[int | str, ...]]
The input data at this loc that caused the error.
Type: _Any
Values which are required to render the error message, and could hence be useful in rendering custom error messages. Also useful for passing custom error data forward.
Type: _NotRequired[dict[str, _Any]]
SchemaError
Section titled “SchemaError”Bases: Exception
Information about errors that occur while building a SchemaValidator or SchemaSerializer.
Methods
Section titled “Methods”error_count
Section titled “error_count”def error_count() -> intReturns
Section titled “Returns”int -- The number of errors in the schema.
errors
Section titled “errors”def errors() -> list[ErrorDetails]Returns
Section titled “Returns”list[ErrorDetails] -- A list of ErrorDetails for each error in the schema.
PydanticCustomError
Section titled “PydanticCustomError”Bases: ValueError
A custom exception providing flexible error handling for Pydantic validators.
You can raise this error in custom validators when you'd like flexibility in regards to the error type, message, and context.
Constructor Parameters
Section titled “Constructor Parameters”error_type : LiteralString
The error type.
message_template : LiteralString
The message template.
context : dict[str, Any] | None Default: None
The data to inject into the message template.
Attributes
Section titled “Attributes”context
Section titled “context”Values which are required to render the error message, and could hence be useful in passing error data forward.
The error type associated with the error. For consistency with Pydantic, this is typically a snake_case string.
Type: str
message_template
Section titled “message_template”The message template associated with the error. This is a string that can be formatted with context variables in {curly_braces}.
Type: str
Methods
Section titled “Methods”message
Section titled “message”def message() -> strThe formatted message associated with the error. This presents as the message template with context variables appropriately injected.
Returns
Section titled “Returns”PydanticKnownError
Section titled “PydanticKnownError”Bases: ValueError
A helper class for raising exceptions that mimic Pydantic's built-in exceptions, with more flexibility in regards to context.
Unlike PydanticCustomError, the error_type argument must be a known ErrorType.
Constructor Parameters
Section titled “Constructor Parameters”error_type : ErrorType
The error type.
context : dict[str, Any] | None Default: None
The data to inject into the message template.
Attributes
Section titled “Attributes”context
Section titled “context”Values which are required to render the error message, and could hence be useful in passing error data forward.
The type of the error.
Type: ErrorType
message_template
Section titled “message_template”The message template associated with the provided error type. This is a string that can be formatted with context variables in {curly_braces}.
Type: str
Methods
Section titled “Methods”message
Section titled “message”def message() -> strThe formatted message associated with the error. This presents as the message template with context variables appropriately injected.
Returns
Section titled “Returns”PydanticOmit
Section titled “PydanticOmit”Bases: Exception
An exception to signal that a field should be omitted from a generated result.
This could span from omitting a field from a JSON Schema to omitting a field from a serialized result. Upcoming: more robust support for using PydanticOmit in custom serializers is still in development. Right now, this is primarily used in the JSON Schema generation process.
For a more in depth example / explanation, see the customizing JSON schema docs.
PydanticUseDefault
Section titled “PydanticUseDefault”Bases: Exception
An exception to signal that standard validation either failed or should be skipped, and the default value should be used instead.
This warning can be raised in custom validation functions to redirect the flow of validation.
For an additional example, see the validating partial json data section of the Pydantic documentation.
PydanticSerializationError
Section titled “PydanticSerializationError”Bases: ValueError
An error raised when an issue occurs during serialization.
In custom serializers, this error can be used to indicate that serialization has failed.
Constructor Parameters
Section titled “Constructor Parameters”message : str
The message associated with the error.
PydanticSerializationUnexpectedValue
Section titled “PydanticSerializationUnexpectedValue”Bases: ValueError
An error raised when an unexpected value is encountered during serialization.
This error is often caught and coerced into a warning, as pydantic-core generally makes a best attempt at serializing values, in contrast with validation where errors are eagerly raised.
This is often used internally in pydantic-core when unexpected types are encountered during serialization, but it can also be used by users in custom serializers, as seen above.
Constructor Parameters
Section titled “Constructor Parameters”message : str
The message associated with the unexpected value.
Bases: SupportsAllComparisons
A URL type, internal logic uses the url rust crate originally developed by Mozilla.
MultiHostUrl
Section titled “MultiHostUrl”Bases: SupportsAllComparisons
A URL type with support for multiple hosts, as used by some databases for DSNs, e.g. https://foo.com,bar.com/path.
Internal URL logic uses the url rust crate originally developed by Mozilla.
MultiHostHost
Section titled “MultiHostHost”Bases: _TypedDict
A host part of a multi-host URL.
Attributes
Section titled “Attributes”username
Section titled “username”The username part of this host, or None.
password
Section titled “password”The password part of this host, or None.
The host part of this host, or None.
The port part of this host, or None.
ArgsKwargs
Section titled “ArgsKwargs”A construct used to store arguments and keyword arguments for a function call.
This data structure is generally used to store information for core schemas associated with functions (like in an arguments schema). This data structure is also currently used for some validation against dataclasses.
Attributes
Section titled “Attributes”The arguments (inherently ordered) for a function call.
kwargs
Section titled “kwargs”The keyword arguments for a function call.
Bases: Generic[_T]
Similar to Rust's Option::Some type, this identifies a value as being present, and provides a way to access it.
Generally used in a union with None to different between "some value which could be None" and no value.
Attributes
Section titled “Attributes”Returns the value wrapped by Some.
Type: _T
TzInfo
Section titled “TzInfo”Bases: tzinfo
An pydantic-core implementation of the abstract datetime.tzinfo class.
Methods
Section titled “Methods”tzname
Section titled “tzname”def tzname(dt: datetime.datetime | None) -> str | NoneReturn the time zone name corresponding to the datetime object dt, as a string.
For more info, see tzinfo.tzname.
Returns
Section titled “Returns”utcoffset
Section titled “utcoffset”def utcoffset(dt: datetime.datetime | None) -> datetime.timedelta | NoneReturn offset of local time from UTC, as a timedelta object that is positive east of UTC. If local time is west of UTC, this should be negative.
More info can be found at tzinfo.utcoffset.
Returns
Section titled “Returns”def dst(dt: datetime.datetime | None) -> datetime.timedelta | NoneReturn the daylight saving time (DST) adjustment, as a timedelta object or None if DST information isn't known.
More info can be found attzinfo.dst.
Returns
Section titled “Returns”fromutc
Section titled “fromutc”def fromutc(dt: datetime.datetime) -> datetime.datetimeAdjust the date and time data associated datetime object dt, returning an equivalent datetime in self's local time.
More info can be found at tzinfo.fromutc.
Returns
Section titled “Returns”ErrorTypeInfo
Section titled “ErrorTypeInfo”Bases: _TypedDict
Gives information about errors.
Attributes
Section titled “Attributes”The type of error that occurred, this should be a "slug" identifier that changes rarely or never.
Type: ErrorType
message_template_python
Section titled “message_template_python”String template to render a human readable error message from using context, when the input is Python.
Type: str
example_message_python
Section titled “example_message_python”Example of a human readable error message, when the input is Python.
Type: str
message_template_json
Section titled “message_template_json”String template to render a human readable error message from using context, when the input is JSON data.
Type: _NotRequired[str]
example_message_json
Section titled “example_message_json”Example of a human readable error message, when the input is JSON data.
Type: _NotRequired[str]
example_context
Section titled “example_context”Example of context values.
to_json
Section titled “to_json”def to_json(
value: Any,
*,
indent: int | None = None,
ensure_ascii: bool = False,
include: _IncEx | None = None,
exclude: _IncEx | None = None,
by_alias: bool = True,
exclude_none: bool = False,
round_trip: bool = False,
timedelta_mode: Literal['iso8601', 'float'] = 'iso8601',
temporal_mode: Literal['iso8601', 'seconds', 'milliseconds'] = 'iso8601',
bytes_mode: Literal['utf8', 'base64', 'hex'] = 'utf8',
inf_nan_mode: Literal['null', 'constants', 'strings'] = 'constants',
serialize_unknown: bool = False,
fallback: Callable[[Any], Any] | None = None,
serialize_as_any: bool = False,
polymorphic_serialization: bool | None = None,
context: Any | None = None,
) -> bytesSerialize a Python object to JSON including transforming and filtering data.
This is effectively a standalone version of SchemaSerializer.to_json.
Returns
Section titled “Returns”bytes -- JSON bytes.
Parameters
Section titled “Parameters”value : Any
The Python object to serialize.
indent : int | None Default: None
If None, the JSON will be compact, otherwise it will be pretty-printed with the indent provided.
ensure_ascii : bool Default: False
If True, the output is guaranteed to have all incoming non-ASCII characters escaped. If False (the default), these characters will be output as-is.
include : _IncEx | None Default: None
A set of fields to include, if None all fields are included.
exclude : _IncEx | None Default: None
A set of fields to exclude, if None no fields are excluded.
by_alias : bool Default: True
Whether to use the alias names of fields.
exclude_none : bool Default: False
Whether to exclude fields that have a value of None.
round_trip : bool Default: False
Whether to enable serialization and validation round-trip support.
timedelta_mode : Literal['iso8601', 'float'] Default: 'iso8601'
How to serialize timedelta objects, either 'iso8601' or 'float'.
temporal_mode : Literal['iso8601', 'seconds', 'milliseconds'] Default: 'iso8601'
How to serialize datetime-like objects (datetime, date, time), either 'iso8601', 'seconds', or 'milliseconds'. iso8601 returns an ISO 8601 string; seconds returns the Unix timestamp in seconds as a float; milliseconds returns the Unix timestamp in milliseconds as a float.
bytes_mode : Literal['utf8', 'base64', 'hex'] Default: 'utf8'
How to serialize bytes objects, either 'utf8', 'base64', or 'hex'.
inf_nan_mode : Literal['null', 'constants', 'strings'] Default: 'constants'
How to serialize Infinity, -Infinity and NaN values, either 'null', 'constants', or 'strings'.
serialize_unknown : bool Default: False
Attempt to serialize unknown types, str(value) will be used, if that fails "<Unserializable {value_type} object>" will be used.
fallback : Callable[[Any], Any] | None Default: None
A function to call when an unknown value is encountered, if None a PydanticSerializationError error is raised.
serialize_as_any : bool Default: False
Whether to serialize fields with duck-typing serialization behavior.
polymorphic_serialization : bool | None Default: None
Whether to use model and dataclass polymorphic serialization for this call.
context : Any | None Default: None
The context to use for serialization, this is passed to functional serializers as info.context.
Raises
Section titled “Raises”PydanticSerializationError-- If serialization fails and nofallbackfunction is provided.
from_json
Section titled “from_json”def from_json(
data: str | bytes | bytearray,
*,
allow_inf_nan: bool = True,
cache_strings: bool | Literal['all', 'keys', 'none'] = True,
allow_partial: bool | Literal['off', 'on', 'trailing-strings'] = False,
) -> AnyDeserialize JSON data to a Python object.
This is effectively a faster version of json.loads(), with some extra functionality.
Returns
Section titled “Returns”Any -- The deserialized Python object.
Parameters
Section titled “Parameters”data : str | bytes | bytearray
The JSON data to deserialize.
allow_inf_nan : bool Default: True
Whether to allow Infinity, -Infinity and NaN values as json.loads() does by default.
cache_strings : bool | Literal['all', 'keys', 'none'] Default: True
Whether to cache strings to avoid constructing new Python objects, this should have a significant impact on performance while increasing memory usage slightly, all/True means cache all strings, keys means cache only dict keys, none/False means no caching.
allow_partial : bool | Literal['off', 'on', 'trailing-strings'] Default: False
Whether to allow partial deserialization, if True JSON data is returned if the end of the input is reached before the full object is deserialized, e.g. ["aa", "bb", "c would return ['aa', 'bb']. 'trailing-strings' means any final unfinished JSON string is included in the result.
Raises
Section titled “Raises”ValueError-- If deserialization fails.
to_jsonable_python
Section titled “to_jsonable_python”def to_jsonable_python(
value: Any,
*,
include: _IncEx | None = None,
exclude: _IncEx | None = None,
by_alias: bool = True,
exclude_none: bool = False,
round_trip: bool = False,
timedelta_mode: Literal['iso8601', 'float'] = 'iso8601',
temporal_mode: Literal['iso8601', 'seconds', 'milliseconds'] = 'iso8601',
bytes_mode: Literal['utf8', 'base64', 'hex'] = 'utf8',
inf_nan_mode: Literal['null', 'constants', 'strings'] = 'constants',
serialize_unknown: bool = False,
fallback: Callable[[Any], Any] | None = None,
serialize_as_any: bool = False,
polymorphic_serialization: bool | None = None,
context: Any | None = None,
) -> AnySerialize/marshal a Python object to a JSON-serializable Python object including transforming and filtering data.
This is effectively a standalone version of SchemaSerializer.to_python(mode='json').
Returns
Section titled “Returns”Any -- The serialized Python object.
Parameters
Section titled “Parameters”value : Any
The Python object to serialize.
include : _IncEx | None Default: None
A set of fields to include, if None all fields are included.
exclude : _IncEx | None Default: None
A set of fields to exclude, if None no fields are excluded.
by_alias : bool Default: True
Whether to use the alias names of fields.
exclude_none : bool Default: False
Whether to exclude fields that have a value of None.
round_trip : bool Default: False
Whether to enable serialization and validation round-trip support.
timedelta_mode : Literal['iso8601', 'float'] Default: 'iso8601'
How to serialize timedelta objects, either 'iso8601' or 'float'.
temporal_mode : Literal['iso8601', 'seconds', 'milliseconds'] Default: 'iso8601'
How to serialize datetime-like objects (datetime, date, time), either 'iso8601', 'seconds', or 'milliseconds'. iso8601 returns an ISO 8601 string; seconds returns the Unix timestamp in seconds as a float; milliseconds returns the Unix timestamp in milliseconds as a float.
bytes_mode : Literal['utf8', 'base64', 'hex'] Default: 'utf8'
How to serialize bytes objects, either 'utf8', 'base64', or 'hex'.
inf_nan_mode : Literal['null', 'constants', 'strings'] Default: 'constants'
How to serialize Infinity, -Infinity and NaN values, either 'null', 'constants', or 'strings'.
serialize_unknown : bool Default: False
Attempt to serialize unknown types, str(value) will be used, if that fails "<Unserializable {value_type} object>" will be used.
fallback : Callable[[Any], Any] | None Default: None
A function to call when an unknown value is encountered, if None a PydanticSerializationError error is raised.
serialize_as_any : bool Default: False
Whether to serialize fields with duck-typing serialization behavior.
polymorphic_serialization : bool | None Default: None
Whether to use model and dataclass polymorphic serialization for this call.
context : Any | None Default: None
The context to use for serialization, this is passed to functional serializers as info.context.
Raises
Section titled “Raises”PydanticSerializationError-- If serialization fails and nofallbackfunction is provided.
__version__
Section titled “__version__”Type: str