Pydantic Field¶

FastDepends is able to use pydantic.Field as a default parameter to validate incoming argument

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from pydantic import Field
from fast_depends import inject

@inject
def func(a: str = Field(..., max_length=32)):
    ...

All available fields are:

• default: (a positional argument) the default value of the field. Since the Field replaces the field's default, this first argument can be used to set the default. Use ellipsis (...) to indicate the field is required.
• default_factory: a zero-argument callable that will be called when a default value is needed for this field. Among other purposes, this can be used to set dynamic default values. It is forbidden to set both default and default_factory.
• alias: the public name of the field
• const: this argument must be the same as the field's default value if present.
• gt: for numeric values (int, float, Decimal), adds a validation of "greater than" and an annotation of exclusiveMinimum to the JSON Schema
• ge: for numeric values, this adds a validation of "greater than or equal" and an annotation of minimum to the JSON Schema
• lt: for numeric values, this adds a validation of "less than" and an annotation of exclusiveMaximum to the JSON Schema
• le: for numeric values, this adds a validation of "less than or equal" and an annotation of maximum to the JSON Schema
• multiple_of: for numeric values, this adds a validation of "a multiple of" and an annotation of multipleOf to the JSON Schema
• max_digits: for Decimal values, this adds a validation to have a maximum number of digits within the decimal. It does not include a zero before the decimal point or trailing decimal zeroes.
• decimal_places: for Decimal values, this adds a validation to have at most a number of decimal places allowed. It does not include trailing decimal zeroes.
• min_items: for list values, this adds a corresponding validation and an annotation of minItems to the JSON Schema
• max_items: for list values, this adds a corresponding validation and an annotation of maxItems to the JSON Schema
• unique_items: for list values, this adds a corresponding validation and an annotation of uniqueItems to the JSON Schema
• min_length: for string values, this adds a corresponding validation and an annotation of minLength to the JSON Schema
• max_length: for string values, this adds a corresponding validation and an annotation of maxLength to the JSON Schema
• allow_mutation: a boolean which defaults to True. When False, the field raises a TypeError if the field is assigned on an instance. The model config must set validate_assignment to True for this check to be performed.
• regex: for string values, this adds a Regular Expression validation generated from the passed string and an annotation of pattern to the JSON Schema