usse/scrape/venv/lib/python3.10/site-packages/cattrs/preconf/pyyaml.py
2023-12-22 15:26:01 +01:00

61 lines
1.9 KiB
Python

"""Preconfigured converters for pyyaml."""
from datetime import date, datetime
from typing import Any, Type, TypeVar, Union
from yaml import safe_dump, safe_load
from cattrs._compat import FrozenSetSubscriptable
from ..converters import BaseConverter, Converter
from ..strategies import configure_union_passthrough
from . import validate_datetime
T = TypeVar("T")
def validate_date(v, _):
if not isinstance(v, date):
raise ValueError(f"Expected date, got {v}")
return v
class PyyamlConverter(Converter):
def dumps(self, obj: Any, unstructure_as: Any = None, **kwargs: Any) -> str:
return safe_dump(self.unstructure(obj, unstructure_as=unstructure_as), **kwargs)
def loads(self, data: str, cl: Type[T]) -> T:
return self.structure(safe_load(data), cl)
def configure_converter(converter: BaseConverter):
"""
Configure the converter for use with the pyyaml library.
* frozensets are serialized as lists
* string enums are converted into strings explicitly
* datetimes and dates are validated
"""
converter.register_unstructure_hook(
str, lambda v: v if v.__class__ is str else v.value
)
# datetime inherits from date, so identity unstructure hook used
# here to prevent the date unstructure hook running.
converter.register_unstructure_hook(datetime, lambda v: v)
converter.register_structure_hook(datetime, validate_datetime)
converter.register_structure_hook(date, validate_date)
configure_union_passthrough(
Union[str, bool, int, float, None, bytes, datetime, date], converter
)
def make_converter(*args: Any, **kwargs: Any) -> PyyamlConverter:
kwargs["unstruct_collection_overrides"] = {
FrozenSetSubscriptable: list,
**kwargs.get("unstruct_collection_overrides", {}),
}
res = PyyamlConverter(*args, **kwargs)
configure_converter(res)
return res