Light Types

"Parse, don't validate"

Compatible with PydanticV2

Inspired by Phantom types

Examples

Sample

from light_types import LightType


class StartsWithString(str, LightType):
    @classmethod
    def validate(cls, value: str) -> bool:
        return value.startswith("String")

With Pydantic

from light_types import LightType


class StartsWithString(str, LightType):
    @classmethod
    def validate(cls, value: str) -> bool:
        return value.startswith("String")

class MyModel(BaseModel):
    value: StartsWithString

assert TypeAdapter(MyModel).validate_python({"value": "StringOk"})

QLightType

from light_types import QLightType, NumericQ

class NumericBetween5And10(int, QLightType):
    validator = (NumericQ() > 5).custom(lambda n: n < 10)

from light_types import QLightType, StringQ

class StartsWithString(str, QLightType):
    validator = StringQ().startswith("String")

from light_types import QLightType, StringQ

class StringWith2O(str, QLightType):
    validator = StringQ().startswith("String") & StringQ().custom(lambda s: s.count("o") >= 2)

from light_types import QLightType, StringQ

class StringWith2O(str, QLightType):
    validator = StringQ().startswith("String") | ~StringQ().custom(lambda s: s.count("o") >= 2)

from light_types import QLightType, StringQ, LengthQ

class StringWith2O(str, QLightType):
    validator = StringQ().startswith("foo") & (LengthQ[str]() > 5)

Tests, linting, formatting

• rye test | lint | fmt