Field validators can be chained.
from dictify import Field
username = Field(required=True).instance(str).match(r"[a-zA-Z0-9 ._-]+$")
instance(type_)¶
Verify that the assigned value is an instance of the given type.
For Model fields, prefer annotations for the base type. instance(...) remains useful for standalone Field validation and compatibility.
email = Field().instance(str)
email.value = "user@example.com"
number = Field().instance((int, float))
number.value = 0
number.value = 0.1
listof(type_=UNDEF, validate=None)¶
Validate that the value is a list, optionally checking each member type and applying a member validator.
from datetime import datetime
days = Field().listof(str)
days.value = ["Mo", "Tu", "We"]
def timestamp_validate(value):
datetime.fromisoformat(value)
timestamps = Field().listof(str, validate=timestamp_validate)
timestamps.value = ["2021-06-15T05:10:33.376787"]
For Model classes, you can often use list[Contact] in the annotation instead.
match(regex, flags=0)¶
Use re.match() against the assigned value.
email = Field(required=True).instance(str).match(r".+@.+")
search(regex, flags=0)¶
Use re.search() against the assigned value.
text = Field().instance(str).search(r"dictify")
model(model_cls)¶
Validate nested document data through another Model.
from typing import Annotated
from dictify import Field, Model
class Money(Model):
unit: Annotated[
str,
Field(required=True).verify(lambda value: value in ["USD", "GBP"]),
]
amount: Annotated[int | float, Field(required=True)]
payment = Field().model(Money)
payment.value = {"unit": "USD", "amount": 10.0}
For Model classes, you can often use Money directly in the annotation instead.
verify(func, message=None)¶
Use a predicate-style callable for validation.
The callable may raise its own exception or return a truthy value. Falsy
return values fail validation and surface as Field.VerifyError.
age = Field().instance(int).verify(
lambda value: 0 <= value <= 150,
"Age range must be 0 to 150",
)
func(fn)¶
Use a callable to transform or validate the value.
If the callable returns a value, that value becomes the field value. If it
raises an exception, validation fails and surfaces as Field.VerifyError.
from datetime import datetime
timestamp = Field().instance(str).func(datetime.fromisoformat)